Lost Inernet, Help me troubleshoot my network connection!

I rebooted my PC this morning and I seem to have lost internet connectivity.

A few days back I installed TweakXp and let it optimise my PC. This may be the culprit.

Anyway

* The router is fine, I am using my laptop on it now.
* i can't connect to my router by going 198.192.0.1 like normal
* Cable is plugged in fine, even shows up on the front of the router
* My network adaprter constantly says 'Acquiring network address'
* Looking at my network adapter is is not receiving or sending any packets.
* I don't have an IP address when I do Ipconfig /all
* If i do ipconfig /release it says this has already been done
* If i do ipconfig /renew is says 'The RPC server is unavailable'

he;lp!

Download this and transfer it to your PC however you can....USB thumb drive or cd burner...

http://www.snapfiles.com/get/winsockxpfix.html

Just tried it, still no joy