hi, after I start windows, taskbar and desktop lock up in about 3-5 minutes. I cannot do anything, except ctrl.+alt+del and log off and log in, then it works again for 2-3 minutes and locks up. also, if I have a browser open, then thre is no problem working in it. neither cause some other programes, like games some problem, they work fine too. but windows taskbar and explorer seem to freeze. problem ocuured after I installed steam. I already uninstalled it and did system restore, but it doesn't help. please, help