If it only happens with this computer (ie you've done a "back end" computer change), you can reread everything we've suggested (and some changes still pending) or go to...
Computer freezing 101:
http://forums.techarena.in/showthread.php?t=481151Computer freezing 102:
http://www.computerhope.com/issues/ch000690.htmOK, OK, so they say similar things in different orders, but it shows that our suggestions are pretty good.
Good luck!