disk read error after clean install

hi guys, i got a pc off ebay with no operating system on it. i downloaded an xp sp3 iso from a torrent site with good comments(i have the serial for xp, just not the disc) and i installed it just fine, but when i start up the computer it says a disc read error has occurred and prompts me to restart. it has 2x500gb hard-drives and im not sure what hard drive i installed it on. please help me to install xp properly or fix this problem so i can use the computer!!! thanks, addy.:smile: