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43 - Install Windows from many ISO files all on one Flash drive using FiraDisk

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This method describes how you can place all your Windows Vista 32-bit/64-bit ISOs, Windows 7 32-bit/64-bit ISOs, Server 2K8 ISOs etc. all one just one (large) USB Flash drive and install any version of Windows onto any system whenever you like.

This is a slightly neater alternative to tutorial #32 and uses FiraDisk.

Most of this is directly 'pinched' from a post by Karyonix (thanks!) on (this post) but I have added the AutoUnattend.xml file so that the process is completely automatic if using a USB Flash drive.

All ISO files must be kept in one single folder (called \ISO in this example. but you can change it) and if you want the user choice feature to work, then the ISO folder must also contain a marker file called 'Choose_an_iso'. Note that the ISO folder that contains the ISO files and the special tag/marker file Choose_an_Iso can be on any drive (e.g. a hard disk or a USB hard disk). You can change the name of the folder or marker file if you like, as long as you also change the path and name in the menu or you can just use one of your iso files as the marker file and delete the 'Choose_an_iso' file so it is not listed when the iso files are listed on the screen.


Update 26 June 2011: Fixed 64-bit Windows ISO install which did not work, as devcon did not include an amd64 version and extraction of the x64-bit version is very awkward! The 64-bit version of devcon from the MS site KB article download (2003) does not actually run under 64-bit WinPE as it is an ia64 platform version!!! Please use the new version of my zip download which now includes both devcon versions (32&64).
Update 26 June 2011 (19:00 BST): Added an Addendum to support hard disks and included two new files in the tutorial download.
Updated 1st July 2011: Changed menu to not use wenv and use grub4dos variables instead, also now allows boot from BOOTMGR or non-ISO9660 iso files. New download
Updated 20th July 2011: Typo in loadiso.cmd meant it reported devcon as missing - now fixed (thanks G R!).
Updated 10th August 2011: Sushil1576 from has found the if X:\Setup.exe is run, you also get the repair option. This is useful for the Hard Disk version only - see Addendum section at the end of this page. The download has been updated with a new MySetup.cmd file so that the Repair option is offered.
Updated 12th September 2011: Modification to add the 'Repair' option for all ISOs, so that no separate 'repair grub4dos' menu item is required

2. Prepare a USB hard drive following the instructions below for a Flash drive. Then copy the AutoUnattend.xml file to any spare USB flash drive that you have. To install Windows, boot from the USB hard drive but make sure the USB Flash drive is also connected to the same system.
- OR -
3. Prepare a USB hard drive following the instructions for a Flash drive below. When Windows Setup loads, press SHIFT+F10 to open a command console and type F:\firadisk\loadiso  (where F: is the drive letter of your USB hard disk - which may vary).
 - OR -
4. See Addendum below for how to modify each Windows Vista/7/2K8 ISO so that a single bootable USB hard drive can be used, without a flash drive being needed and without the need for the user typing in extra commands.

Method (for USB Flash drives)

Note: the instructions below also apply if you already have a bootable grub4dos disk, just extract the contents onto it (note that it will overwrite your menu.lst though!) and copy all your ISO files and overwrite your grldr file with the recent one included in the latest version of RMPrepUSB v2.1.623 or later.

1. Create a new folder on your hard drive called C:\WINFira

2. Download the zip file from the Beta Downloads - Tutorials page and extract the contents to the C:\WINFira folder

Contents of

\FiraDisk folder
wenv                (not used in this tutorial)
mysetup.cmd   (not actually used - see Addendum below)
winpeshl.ini      (not actually used - see Addendum below)
\ISO folder
          <<<<<<<    (your iso files go here)

3. Now copy your Windows install ISO files to the C:\WinFira\ISO folder - Note: the iso filenames must NOT contain spaces!

You can download some Windows 7 ISOs from here.

4. The sample menu.lst contains 3 menu entries. The first menu entry is set to boot a fixed iso name. Just copy the first menu entry to make as many more as you like for all your ISO files. The second menu entry is merely to allow you to reboot to your hard disk after Windows has been installed onto it. The last menu entry allows the user to choose which iso to boot to, by getting the user to type in the name of the iso that they want to use. You can delete any menu entries that you do not require.

Edit the menu.lst and change the first line (title) and second line (ISO filename) in each menu, the sample menu included in the download, is shown below:

#       NORMAL     HIGHLIGHT     HELPTEXT        HEADING    in pairs consisting of foreground/background
color black/cyan    blue/cyan        red/light-blue     red/cyan

# display this heading
write (md)0x220+1 !BAT\necho -n -P:0000 $[0133]                    --- Windows install ---                                    \0
initscript (md)0x220+1

title 1 INSTALL Windows 7 32-bit\nThis will install any edition of Windows 32-bit to your hard disk
debug off
set MYISO=win7.iso
dd if=()/firadisk/au.xml of=()/AutoUnattend.xml
map --mem (md)0x800+4 (99)
map /ISO/%MYISO% (0xff)
map (hd0) (hd1)
map (hd1) (hd0)
map --hook
write (99) [FiraDisk]\nStartOptions=cdrom,vmem=find:/ISO/%MYISO%;\n\0
chainloader (0xff)/BOOTMGR || chainloader (0xff)


root ()

title 2 Boot from 1st Hard Disk \nBoot from MBR of first hard disk and remove the USB drive
map (hd0) (hd1)
map (hd1) (hd0)
map --hook
chainloader (hd0)+1
rootnoverify (hd0)

root ()

title Choose any iso file...
root ()

title 3 INSTALL WINDOWS - Boot from any Windows ISO to install Windows\nThis menu allows you to type in the name of any Windows ISO file and boot from it
# find the ISO folder by looking for a marker file
debug off
find --set-root /ISO/choose_an_iso
# list all files in the /ISO folder so the user can see them
ls ()/ISO/
# Ask user which iso they want (name is converted to uppercase as /u is specified)
set /p /u ask=Enter iso filename WITH NO .ISO EXTENSION (e.g. Win7Pro32 ) :  
if "%ask%"=="" echo No iso file specified! && configfile /menu.lst
# check if user entered a valid filename with no ISO extension!
ls /ISO/%ask%.iso || echo Cannot find /ISO/%ask%.iso !!! && pause --wait=3 && configfile (bd)/menu.lst
echo Loading /ISO/%ask%.iso - please wait ...
#set root drive to USB stick
find --set-root /firadisk/loadiso.cmd
map --mem (md)0x800+4 (99)
dd if=()/firadisk/au.xml of=()/AutoUnattend.xml
find --set-root /ISO/%ask%.iso
# run the grub4dos map command and specify the iso file we want to load
map /ISO/%ask%.iso (0xff)
map (hd0) (hd1)
map (hd1) (hd0)
map --hook
# Specify the same iso file for when firadisk runs in winpe
find --set-root /firadisk/loadiso.cmd
write (99) [FiraDisk]\nStartOptions=cdrom,vmem=find:/ISO/%ask%.iso;\n\0
chainloader (0xff)/BOOTMGR || chainloader (0xff)

5. Now prepare a USB Flash drive using RMPrepUSB (optional - if you already have a bootable USB drive with grub4dos)

    Run RMPrepUSB (use v2.1.622 or later)
        To wipe and format the USB drive (optional) - set the following options in RMPrepUSB:
        1. MAX
        2. (any volume name you like!)
        3. WinPE v2/v3 (or DOS or FreeDOS or XP)
        4. FAT32 or NTFS (or FAT16 but it has a 2GB limit)  and also select the Boot as HDD option
        5. Tick Copy OS Files box and set the Copy Folder to C:\WINFIRA
        6. Click Prepare Drive to format the drive and copy the files over

      NOTE: Whether you already have an existing grub4dos USB drive or have just formatted one as detailed above, you need to install the latest version of grub4dos as follows:
Now click on Install grub4dos and choose Yes for MBR and hit Enter to copy across the grldr file. You need the correct grub4dos grldr file as this supports some newer grub4dos commands.

Contents of bootable grub4dos drive:

grldr   (new 'chenall build' version as used by latest RMPrepUSB)
\FiraDisk folder
\ISO folder
(your iso files go here) <<<<<<<<<<<<<<<<<<<<<<<<<<<<< (use short names if possible to avoid typing!)

That's it!
To test your menu, run RMPrepUSB and hit F11 to run the QEMU emulator (you do not need to create a virtual hard disk so enter 0 when prompted). Note that you can only test the menu out using this method, once the ISO starts to runs it seems to crash under QEMU!

                This is the unchanged menu.lst provided with the download. You can add more entries or delete the ones you do not want.

Now go boot it and install Windows on something - you should see the blue Windows Command Shell window flash up briefly and install the FiraDisk driver and load the ISO file when Windows Setup starts. If a repair utility is present, you will be asked if you want to try to repair the current installation.

The screenshot below shows the INSTALL WINDOWS - Boot from any Windows ISO menu option action.

The grub4dos menu will look for a marker file (the file '\ISO\Choose_an_iso') on every drive and list the files in that folder when it finds it, so that the user can choose one of them...

The Install Windows from any ISO list is presented to the user.

Note: you must use the USB drive on a real system - WinPE needs to see a removable drive containing the AutoUnattend.xml file.

You may have problems using an emulator such as QEMU as the dd command needs a writeable drive in order to succeed - but most emulators do not allow writes to physical drives such as USB drives.

Once your OS has installed, if the system reboots back to the USB drive again, just use the 3rd menu item to boot from the hard disk (or just remove the USB drive and reboot).

Note: To add a standard XP install ISO to your USB drive, see Tutorial #30.

Addendum - How to use this technique on a bootable USB Hard drive

The auto-detection of \AutoUnattend.xml will not work if you use a hard drive (neither USB nor IDE/SATA) as a hard drive is not a 'removable' disk, we need to patch the ISO files themselves so that they will automatically run the LOADISO.CMD from the boot drive. To do this we need to copy the contents of the ISO file to an empty folder, modify the ISO file contents and then create a new version of the ISO file.

1. On your Windows system, Mount the ISO that you want to modify using ImDisk or Virtual CloneDrive or any suitable tool and extract all the contents to an empty folder on your hard drive (e.g. C:\TESTISO)
2. If you want to be able to install any edition of Windows (e.g. all SKUs rather than just Professional), then delete the C:\TESTISO\SOURCES\EI.CFG file.
3. Run a WAIK command prompt as Administrator (found in the Start Menu after installing WAIK) and mount the C:\TESTISO\Sources\boot.wim file (use Imagex /info to determine the correct image number that you need to mount, usually this is Index #2 - but not always!). e.g.

imagex /info C:\TESTISO\SOURCES\boot.wim
(check what images you have by looking at the output)
mkdir c:\mount
imagex /mountrw C:\TESTISO\SOURCES\boot.wim 2 c:\mount

4. Now we just need to copy the two files to the C:\mount\windows\system32 folder - winpeshl.ini and mysetup.cmd. Use the ones in the \FiraDisk folder inside the tutorial download. Their contents are shown below just for reference:


@echo off

REM run wpeinit after loading ISO file

cmd /q /c  "FOR %%i IN (C D E F G H I J K L N M O P Q R S T U V W X Y Z) DO IF EXIST %%i:\FIRADISK\LOADISO.CMD  cmd /k %%i:\FIRADISK\LOADISO.cmd"

REM find RAMDRIVE with ISO contents
for %%I in (C D E F G H I J K L M N O P Q R S T U V W X Y Z) do if exist %%I:\sources\install.wim set RAMdrive=%%I:
If NOT "%RAMdrive%"=="" echo Found Install.wim at %RAMdrive%\sources\install.wim
IF "%RAMdrive%"=="" (
REM Reboot
goto :EOF

echo Run Setup.exe with Repair option from X: drive (if available)
if exist X:\Setup.exe X:\setup.exe

echo looking for setup in root of DVD ISO
If exist %RAMdrive%\setup.exe  (
REM setup will use its path to find the install.wim
goto :RBT

echo looking for setup.exe in \sources on DVD ISO
If exist %RAMdrive%\sources\setup.exe  (
REM setup will use its path to find the install.wim
echo Launching %RAMdrive%\sources\setup.exe
goto :RBT

REM if not then just call setup in root of boot.wim and point it at install.wim
if exist X:\sources\Setup.exe X:\sources\setup.exe /installfrom:%RAMdrive%\sources\install.wim
if exist X:\Setup.exe X:\setup.exe /installfrom:%RAMdrive%\sources\install.wim
goto :RBT

dir X:\ /b
echo Cannot find X:\Setup.exe !
@echo Press a key to reboot now...

wpeutil reboot

Although these two files are located in the \FiraDisk folder inside the Tutorial #43 download for your convenience, they are not actually used in booting and can be deleted from the\FiraDisk folder after copying them to the mounted ISO folder - if you wish.

4. Commit the changes and unmount the mounted image - e.g.

(close any Explorer windows which point at C:\mount first!)
imagex /unmount /commit c:\mount
imagex /cleanup

5. Create a new ISO file from the WAIK command prompt:

 to make a bootable ISO use the command:

oscdimg.exe -b"C:\Program Files\Windows AIK\Tools\PETools\x86\boot\" -u1 -d -h -m -lWIN732SP1 C:\TESTISO\ C:\Win732SP1.iso
  - OR -  for a non-bootable ISO (but still usable for this tutorial and it will still load Windows Setup) use:

oscdimg.exe -u1 -d -h -m     -lWIN732SP1    C:\TESTISO\      C:\Win732SP1.iso

(-l specifies the volume Label - note that the source path C:\TESTISO\ should end in a back-slash!). The -u1 (ISO9660) option ensures that the ISO is readable in both UDF and ISO 9660 (grub4dos readable) format - NOTE: when mounted by grubdos, all filenames will be uppercase - e.g. BOOTMGR not bootmgr. For maximum compatibility (e.g. with WinImage) you can also add -j1 for Joliet format (upper/lower case and long filenames).

6. Now follow the tutorial above but use this new ISO file. The Repair menu options in the menu.lst (menu's 2 and 5 can be deleted as you will be offered the repair option anyway).

7. (optional) The Autounattend.xml file in the root of the USB drive is not required and can be deleted.
                  If you delete the AutoUnattend.xml file, you need also to change the menu.lst slightly and delete the lines that mention AutoUnattend.xml, otherwise the grub4dos menu will give an error as the file no longer exists.

8. The new ISO should allow you to install any Edition of Windows that is contained within the Install.wim file. You can also use the same files on a USB Flash drive if you wish.

Note: MySetup.cmd can run different versions of Setup.exe
X:\Setup.exe will run Setup and offer the Repair Operating System option.
%RAMDRIVE%\Setup.exe and \Sources\Setup.exe will go straight to the 'Install Windows' GUI and will not allow the user to Repair Windows.

If you do not want the Repair option offered, you should comment out the line shown in purple in MySetup.cmd (i.e. place a double colon :: in front of it - or delete the line).


Check you have a recent (2011) version of grub4dos - only later versions support grub4dos variables. If you already have a grub4dos boot drive and do not want to re-format it or install grub4dos using RMPrepUSB, then just copy over the grldr file from the RMPrepUSB folder to your USB boot drive to update it.

If any of the commands fail, try adding a pause command after each line to see which line gives the error:

title Install Windows 7 64-bit Enterprise Edition\nRun the Windows install DVD to install a copy of Windows to your hard disk
echo 1 && pause
find --set-root /Firadisk/loadiso.cmd
echo 2 && pause
set mm=map /ISO/%MYISO% (0xff)
echo %mm%

If the map command fails for 'file not contiguous' - you will need to run WinContig.exe (download from here) on the failing ISO file (on the USB drive) to defrag it. If this fails to work (usually because you do not have enough spare space on the USB drive), then you will need to copy ALL the files from the USB drive to your hard disk, reformat the USB drive using RMPrepUSB as in step 3. It is often faster and easier to re-copy the files than it is to use WinContig on a large USB iso file.

Some grub error numbers are reported here - these may or may not be the same as in grub4dos, but may be useful as a reference.

If Setup seems to want to install the wrong version of Windows (e.g. you are prompted to install Vista Business instead of say Windows 7 Home Premium) check that none of your drives have a file in the folder \SOURCES called INSTALL.WIM - this includes any Windows install DVD-ROM you may have left in your DVD-ROM drive!

Some members of have reported that their system does not detect the AutoUnattend.xml on their USB pen. In one case this turned out to be an unlucky combination of Buffalo USB pen, Server 2008 ISO (not R2) and a Dell Latitude E6400. Other USB pens worked and other OS ISO's worked. Another user reported difficulty with their SanDisk pen. If the blue command console window does not briefly pop-up and run during the boot from the ISO or the first part of the Windows Setup GUI, then press SHIFT+F10 to get a console window and type DISKPART followed by LIST DISK to see if your USB drive is listed (if no USB drive is listed then it means your USB drive is incompatible with the OS ISO your are trying to use) - if the USB drive is not listed, type RESCAN and then LIST DISK to see if it is now listed. If it is you may have an incompatible USB drive - try a different make or model. Use EXIT to quit Diskpart.

Alternatively, try the workaround for Fixed disks at the top of this page (i.e. also insert another different USB pen drive with the AutoUnattend.xml file on it).

If you are using an OEM Recovery Disk ISO file, the AutoUnattend.xml detection may be suppressed. In this case you will have to use the manual method detailed in the workaround for Fixed disks at the top of this page and run a command prompt (SHIFT+F10 may not work so use the OEM Command prompt menu entry instead) - or - unpack the ISO and make a new one without any unattend.xml file in it (the new ISO does not need to be bootable so any 'makeiso' tool will do to make the ISO). 

How it works (when using a USB Flash drive)

The boot/mapping sequence goes like this:

ISO mapped as virtual drive by grub4dos -> load WinPE (ISO drive is now lost as in protected mode) -> find and load AutoUnattend.xml -> find and run \FiraDisk\LoadIso.cmd -> run FiraDisk and load ISO as virtual drive under WinPE (iso filename is passed via ramdrive from grub4dos) -> Exit command shell -> Setup continues and finds \sources\Install.wim on virtual disk loaded by FiraDisk.

  1. The menu.lst basically just maps the ISO file as a DVD-ROM drive (0xff) but this mapping is lost as soon as Setup fully loads up into RAM and enters protected mode. However, we also write the name of the iso file to a ramdrive whilst in the grub4dos menu. We do this because we need to tell FiraDisk the name and path of the ISO file when Setup starts to run.
  2. When the ISO boots, it will prompt you to 'Press any key to boot from the CD or DVD' - because it thinks you are booting from a DVD (tip: press a key!).
  3. Now when a Windows Vista/7/2K8 WinPE based Setup runs, WinPE always tries to look for a file called AutoUnattend.xml or Unattend.xml which has a 'WindowsPE' section containing commands and configuration settings. The file AutoUnattend.xml must be on a Removable disk and not a Fixed disk. Luckily, we just happen to have such a file (\AutoUnattend.xml) on the USB Flash drive (cos we put it there!). This contains a command to run the file \FiraDisk\LOADISO.cmd from wherever it can find it (it searches all drives until it finds it)
  4. LOADISO.cmd runs FiraDisk and maps the ISO file as a virtual drive, ready for Windows Setup to scan and recognise.
  5. We then exit from the LOADISO script to allow WinPE to continue and run Setup.
  6. Setup continues to run once LOADISO has finished executing and starts to look for a drive which has the \sources\install.wim file on it (this contains the Windows images).
  7. Now when Setup looks for the \sources\install.wim file, it finds it on the new virtual drive which was made by FiraDisk and thus continues as normal - just as if it booted from a real DVD.

The way that we pass the correct path for the ISO file is via these lines in menu.lst

map --mem (md)0x800+4 (99)                                                                                creates a new ram drive
write (99) [FiraDisk]\nStartOptions=cdrom,vmem=find:/ISO/win7.iso;\n\0                    writes the name of the iso to the ramdrive - when the FiraDisk driver loads, it will try to find it

When LOADISO loads the FiraDisk driver using devcon.exe, FiraDisk looks for the special grub4dos parameter in memory and then searches all media until it finds the file specified and then loads it as a CD/DVD.

Some ISOs do not allow the user to choose the repair option but instead show all Editions of Windows that are present in the install.wim file if an AutoUnattend.xml is detected and is valid. This is great unless you actually want the Repair option!  To force the repair option to appear, we need to remove the text from within the AutoUnattend.xml file. This is what the dd of=()\Autounattend.xml line does in the 2nd menu. It overwrites the \AutoUnattend.xml file with a lot of spaces. The files must be over 2K in size because the NTFS filesystem (if used on your flash drive) under grub4dos gives an error if the file length is under 2K and you try to use dd.

Forcing the Repair option to be given is done using this line to get rid of the xml content by filling the file with spaces...
dd if=()/ImDisk/spaces.xml of=()/AutoUnattend.xml

or we can load the ISO as a DVD for an install by putting the correct commands into the Autounattend.xml file using...
dd if=()/ImDisk/au.txt of=()/AutoUnattend.xml

Updated on Sep 12, 2011 by Steve Si (Version 100)

Attachments (4)

Tut43Menu.jpg - on Sep 12, 2011 by Steve Si (Version 1)

RMprepwinfira.jpg - on Jul 3, 2011 by Steve Si (Version 1)

firaISOmenu1.jpg - on Jun 25, 2011 by Steve Si (Version 1)

firaISOmenu.jpg - on Jun 25, 2011 by Steve Si (Version 1)