Could be a DNS problem. AIM connects using an IP address, not a server name. MSN and Internet Explorer use DNS to resolve server names to IP addresses.
To test this, do the following:
Click on the
Start button.
Click on
Run.
Type
CMD in the "Open:" box and press
Enter.
In the Command Prompt window, type
ping www.google.com and press
Enter.
Report the results here.
In the Command Prompt window, type
ping 64.233.161.99 and press
Enter.
Report the results here.
If you get replies on the IP address but not on the name, then you have a DNS problem.
To find out whether you have bad DNS server info, or no DNS server info at all, type
ipconfig /all in the Command Prompt and press
Enter and post the results of that here as well.
edit: Fixed a typo in the instructions.