Computer not responsive after a certain time

Hey guys,got this problem recently on my windows xp.Everytime I boot up and use the com it seems normal.After awhile,especially if I leave the com alone for about 15~20 minutes,things become unresponsive.I can't open up my msn messenger,and slowly but surely my programs all start to freeze.I can't even hit ctrl+alt+del to see whats wrong.And though I can access the menu,I can't do a shutdown cos the system just doesn't move after I click the shutdown button.Can any kind soul please help?

Hello,

You may want to try running Spybot - Search & Destroy and Ad-Aware (links in my sig). Then, read this and post a HijackThis log in a new thread in the HijackThis Logs forum. If you are still having issues when your log is declared clean by an expert, post back here and we'll see what we can do.

Regards,

Ax