When you say that your computer freezes, do you actually mean exactly that (i.e. you can't use any programs at all) or is it simply that your browser refuses to download anything from the internet?
If you're getting complete 'lock-ups', the problem is almost certainly nothing to do with your internet connection. You should be looking for viruses, trojans or other malware on your computer.
However, if your browser simply stops downloading anything from the internet, it's probably the same DNS problem which gets reported, here on AB, at least once per week. Try the following.
Disconnect from the internet.
Right-click on the icon for your internet connection.
Select 'Properties'
Click the 'Networking' tab.
Click 'TCP/IP settings'.
Click alongside 'Specify name server addresses'
Replace the row of noughts, alongside 'Primary DNS' with 194.168.4.100
Replace the row of noughts, alongside 'Secondary DNS', with 194.168.8.100
Leave the other settings unchanged.
Click 'OK' twice.
Reconnect to the internet.
Those instructions apply to Windows ME. It's the same with XP (although the 'Networking' tab is, I believe, relabelled as 'Server types'). For Vista, follow the instructions here (but still using the Virgin DNS addresses I've given you above):
http://windowshelp.microsoft.com/Windows/en-us /help/e070bf7b-6d5e-4f49-b4f7-10aa8d8b11e21033 .mspx
Chris