I have a computer with Vista Home that can connect to the router, but it cannot get on the internet. I cannot ping google.com, the request times out. I've tried this on two separate networks and have no trouble with other computers connecting.

I've renewed ipconfig, reset winsock, updated the wireless adapter, and the hosts file looks fine. I've tried disabling the firewall as well as a direct wired connection. I did a scan with Norton and it didn't find anything. Is there anything else I can try before resorting to a system restore?

Update (Copied from Answer)

Windows Update was able to find updates and install them (though, they could have already been downloaded previously). When I pinged Google by using their IP 66.102.9.103, it said it lost 25 percent of the packets. I successfully flushed the DNS but it didn't help. Also, I found safe mode with networking works fine.