Windows xp wont do anything i want it too!

A friend of mine is paying me to fix his computers one computer will not boot any cd i give it it can read the files but if i try to install windows 7 it says
e:/boot
only a part of readprocessmemory or writeprocessmemory request was completed
When i tried to use this http://www.google.com?t=4351583&start=0
and put it on a usb stick it boots then it comes with a product key and i type it in and it says wrong, i have tried more then 5 keys and no luck. Im going to go work on the other pc now so please help me!!
Answer #1
are you trying to install 7 but it has XP now? does it boot up at all…without a cd? & you changed the boot order in the bios?
Answer #2
yes i have done with and without cd attemping to do repiar install of xp with a cd
Answer #3
try using a diff cd / dvd drive ? check the hdd for sector errors
Answer #4
Also try burning another Windows 7 / XP disc.. maybe your disc is faulty.