here's what you do:
 
copy all files from the Windows XP CD to a folder in your hard drive.
 
extract the boot record from the CD using ISOBuster or CDMage. (try google search isobuster, cdmage)
 
load nero burning rom and close the wizard. create new compilation and choose CD-ROM (boot).
 
Boot Tab:
browse the extracted boot record as the source of the image file, check enable expert settings.
 
kind of emulation: No Emulation
load segments of sectors (hex!): 0000
number of loaded sectors: 4
 
ISO Tab:
File/Directory Name Length: ISO Level 1  
Format: Mode 1
Character Set: DOS (important)
check Joliet
check do not add the ';1' ISO file version extension
 
Label Tab:
choose a label for your CD, usually WXPVOL_EN
 
Dates Tab:
use the date and time from original file
 
Misc Tab:
check cache files from disk and network
check cache files smaller than [64] kb
 
Burn Tab:
check Write
check Finalize CD
write method: Disc-at-Once
 
 
drag the files which you copied from the folder of your hard drive to the compilation window.
 
Burn the Disc.