Wow installation error

"Patch data is bad. (source CRC mismatch: -877538840/2044252179) (BNUpdate::PTCApply)"

This is what I get. It comes on installation disc #1, when I changed all my IDE ATA/ATAPI Contollers to PIO, error comes on disc #4 (there is 5 discs). I have also saved installers to my hard drive, then runned without discs and it still gives same shit.

Any help please?

Then you probably get the CRC error, because some file(s) is faulty.
Sometimes, it helps extracting the cd to a folder on the desk, sometimes it dont.
The best way, is probably to return the game from where you bought it if you got it recently?

As I said, I have already saved all installers to my hard drive and it gives the same message.

I think the disc is not the problem, it comes randomly, sometimes on disc #1, sometimes on #4.

By the way, here is my computer info, it should be enough "good" for WoW playing?

AMD Athlon 3000+
GeForce 6600GT 128MB
1024MB RAM
ASUS A8V motherboard
Windows XP Home SP2