unusual problem concerning hard drive,... help

ok... i am running a 733 quicksilver with 512 ram, i have been using limewire a while and did have the crashing problems when i switched to jaguar but those are fixed and it does run faster... but......

after i open the program within 2 to 3 minutes my hard drive starts making extremely loud grinding noises like it is trying to read something and failing.... my shared folder doesn't have that many things in it... i used disk warrior cuz my hard drive volumes were horrible... 33% of directories were in the wrong places... right so i figured that was it rebuilt it and gave it a nother go... still messed up... when it is trying to read and making those noises... everything freezes.. it sucks... i ran virex... no viruses.. i am completely lost as to what could be causing it...i have re installed limewire 3 times... running jag 10.2.1 .... ultrapeer disabled.... ahh i dunno... any ideas whatsoever would be greatful... i like to think i have a somewhat vast knowledge of computers but... this one has got me ...... thanx.