Have you got a Windows 95 or 98 system that you could use to make up a DOS bootdisk on?
If so, put a blank floppy in the drive and type
FORMAT A: /S <RETURN>
then let the disk format, and copy the following files to the disk:
C:\WINDOWS\COMMAND\FDISK.EXE
C:\WINDOWS\COMMAND\FORMAT.COM
C:\WINDOWS\COMMAND\XCOPY.EXE
C:\WINDOWS\COMMAND\XCOPY32.EXE
C:\WINDOWS\HIMEM.SYS
C:\WINDOWS\MSCDEX.EXE
Open the file C:\CONFIG.SYS in Notepad and take a look for a line that starts DEVICE= and bears a resemblance to a CD-ROM drive, such as ATAPI.SYS, CDROM.SYS or something similar. It will have a parameter after the name starting /D:<and then an identifier>, eg /D:MSCD001
Copy this file onto the floppy disk as well.
Open Notepad and copy and paste the following text as A:\CONFIG.SYS (make sure it doesn't get an extra .TXT extension on the end).
DEVICE=A:\HIMEM.SYS /TESTMEM:OFF
DOS=HIGH,UMB
LASTDRIVE=Z
Put a line in relating to the CD-ROM driver as well saying something like
DEVICE=A:\cdromdrive.sys /d:mscd001
and save this as A:\CONFIG.SYS
Copy the following text to Notepad and save as A:\AUTOEXEC.BAT
@ECHO OFF
A:\MSCDEX /D:MSCD001
PATH A

ROMPT $P$G
Next, test the disk. Put it in floppy drive A: and start the PC up. Let it run. You should end up with a prompt saying A:\> after a few messages saying CD-ROM assigned a particular letter. This may be different to what Windows assigns it but it doesn't matter.
Type FDISK <RETURN> and follow the instructions to create a new primary partition of the maximum size, and say yes to make it active. Let the PC reboot off the floppy disk after this has finished. Let the machine boot up again.
Type FORMAT C: /S <RETURN> and let the partition format. Give it an empty volume label when prompted.
Put your Win2K or XP Pro CD in the drive.
Type the following commands at the prompt:
MD C:\I386 <RETURN>
XCOPY x:\I386\*.* C:\I386 /S /E <RETURN>
Replace x with the letter of your CD/DVD drive in the last command.
Once all the files have copied, type the following:
C: <RETURN> (the command prompt should change to C:\>)
CD \I386 <RETURN> (command prompt should change to C:\I386>
WINNT <RETURN> (your operating system installer should fire up).
I have written this off the top of my head, so there is quite a good chance I may have forgotten something. Please feel free to get back to me if these don't work with any error messages and the stage you get to.
John