Windows 7 no internet access

For some odd reason my windows 7 box no longer connects to the internet. It was working just fine then just stopped working about 3 hours ago. I know it is a problem with the system itself as I have a p4 ubuntu box on the same hub and it is working just fine.

I have swapped the cat5 cables around and both work on the ubuntu box. Realtek diag also reports no problems in hardware or with the cable. Also the windows 7 box has normal network access. I can run synergy just fine and browse the network drives and stream content around the network. The main router is an old pentium 3 box running smoothwall and it reports no problems. The problem started out as intermittent and disabling and re-enabling the network adapter would fix it for a while. I have run both anti virus and malware sweeps, both locally and remotely from the ubuntu box and all was clean (I run everything in a sandbox first so my systems are normally clean).

Any ideas on what to do? Side note, I have 4 other computers(1xp, 3 ubuntu) and 2 notebooks(1 xp, 1 ubuntu), all fine with internet access.

The windows 7 box
Windows 7 home pre 64-bit
Intel core i5 750
4gb ddr3 ram
Gigabyte p55a-ud3 motherboard rev 1.0
All driver up to date as of 12 hours ago.