GUIDE: Unlimited XP installations on the same partition (concise)...

[Intuit]

Basically, you can have more than one installation because you can customize the directories unto which WinXP installs to. The endgoal of the following, is to modify your WinNT.SIF file. This is one of the configuration files that WinNT setup reads from to determine how it sets up your system. Here are the very simple steps.

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{0} Backup these files: "Boot.Ini", AutoExec.Bat, Config.Sys, MsDOS.Sys, DriveSpace.Ini, cmldr, ntldr, NTDETECT.COM
........IF YOU MAKE A MISTAKE, SETUP MAY OVERWRITE YOUR EXISTING INSTALLATION. (you may want to backup entirely)

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{1} On the WinXP CD and from within Windows, Run "E:\Setup.Exe /noreboot /makelocalsource".
........It will first ask you “Which type of installation do you wish to perform?" to which you’ll specify “New Installation (Advanced)".
........During Setup, specify the partition and location for your main directory “/SystemRoot\" (C:\Windows).

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{2} Once that is completed (DO NOT REBOOT), locate the directory “$WIN_NT$.~BT".

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{3} USING YOUR ORIGINAL WINNT.SIF FILE AS A BASE, create a customized WinNT.SIF file.

To move and rename “C:\Program Files" ADD:
........[Unattended]
........ProgramFilesDir="D:\Win510 Programs.A"
........CommonProgramFilesDir="D:\Win510 Programs.A\Common Files"
........CommonFilesDir="D:\Win510 Programs.A\Common Files"
........ProgramFilesPath="D:\Win510 Programs.A"

To move and rename “C:\Documents and Settings" ADD:
........[GuiUnattended]
........ProfilesDir="E:\Win510 Users.A"

To move and rename “C:\Windows" VERIFY/ADD:
........(these options are already available in the GUI of setup within Windows… look for the options...)
........
........[data]
........InstallDir="\Win510.A"
........
........[Unattended]
........TargetPath="\Win510.A"

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{4} Once you’ve created the modified WinNT.SIF file and it’s ready, backup the following directories/files to a compressed archive for repeated use, if necessary (incase you make a mistake, this saves much time… simply delete the undesired installation, restore those archived files, remodify the WinNT.SIF and reboot to try again):
........$WIN_NT$.~BT,
........$WIN_NT$.~LS,
........$LDR$,
........BOOT.INI,
........TXTSETUP.SIF

{5} Once that is done, reboot and setup will begin installing to your customized locations.

[Intuit]

Three important notes.

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{A}  ... ERROR ON LINE XX ... messages from Setup:
Eliminate Unicode characters from WinNT.SIF text file and save in ASCII (not UniCode) format.
Pay special attention to and replace all quotation mark characters encasing your "drive:path\filenames".

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{B}  The name for "C:\Windows" when changed, MUST be in a DOS compatible 8.3 name format.  
"\FLDRNAME.ABC", "\12345678.123" is legal and will work,
while "\FOLDERNAME.ABCD", "\123 4567.123" will not work.

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{C}  You can place "C:\Windows" on a different partition or drive, example "D:\Win510.A".
Placing a drive-letter on the paths in "InstallDir" & "TargetPath" mentioned above will not work.
It all hinges on the following...

........[data]
........floppylessbootpath="\Device\HardDisk1\partition0"

"HardDisk0" is assumed to be the first harddisk that the BIOS finds while
"Partition0" is assumed to be the first partition on that harddisk.
Increment the numbers as needed.  Some trial&error experimentation may be necessary.
However, also remember that this may be configurable during the GUI portion of setup as stated above.

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http://www.sudhian.com/index.php?/forums/viewthread/38861/

[Reflex]

So when is the Vista edition of this guide coming?