|Well, ipconfig provides no specific security concerns. Unless you're binding an external IP address to that specific computer and not using a firewall.|
This is like a TCP/IP issue - Without knowing more detail it's difficult to tell specifically (when it drops Internet, can you still ping out by IP - that indicates it's just a DNS issue, etc.)
A lot of time simple troubleshooting will fix these issues, disable/re-enable the network adapter.
But as long as you're running at least XP SP2, you should just force a winsock reset and reinstall TCP/IP by running:
"netsh winsock reset"
from a Command Prompt. (Without the quotes).