When I turn on my computer the internet runs smoothly for about 5-10 minutes.  Then suddenly I can't access any pages on any browser (firefox, IE, Opera), all i get is a blank screen.  However msn and other programs that require the internet still work.  What's going on? If I restart my computer it works again (for 5 mins) but I don't want to restart it every few minutes. Please help.

EDIT: Ran an antivirus scan and I think its fixed, thanks for the help.

Do you have an Antivirus software?  Try doing a antivirus check, kinda same thing happened here when I got infected by clicking on a ".pif" file.

i sometimes find that once my computer has been idle for a while it kinda locks up the internet? it doesnt really bother me seeing as though i only hafta restart the computer and it's fine (take like max 2 minutes)