Failure to boot xp/ blue screen on install

hi guys, i desperatly need help. i recently used pc health advisor software to clean the registry on my sons pc, after restart i started to get 3 short beeps on post. and upon boot it went to windows xp loading screen and just restarted itself. so i tried to reinstall windows xp and got a blue screen with the following error message
"DRIVER_IRQL_NOT_LESS_OR_EQUAL" at the top of page and at bottom was
"ntfs.sys - Address F5AB539F base at F5AB4000, Datestamp 4922d8ed"
i googled the beep codes and replaced memory (which it was saying fault was according to beeps) - no result, so i went and replaced the main board with a brand new one and low and behold it's exactly the same!
my son has only had this system for a week and it was running fine before registry cleaner was used (i have used same one on my windows 8 laptop and it worked fine, also on my wifes windows 7 laptop)
please help guys! this is getting expensive