Internet explorer not resonding

Question

i keep geting randum message internet explorer not responding i have recently made a few changes to my pc flashed my bios because i was going to put vistor on but decided to stay with xp had a few viruses last week but avg says now clean changed my ram from 1 gig to 2 gig everything else apears to be ok also when i have this problem my other desktop and laptop are fine so i dont think its my internet conection anyone got any ideas? thankyou