Windows 7: Why does Tor internet and skype work but not my normal browsers?

I'm connected a server and the internet on it is acting weird
My normal browsers (firefox + Chrome) are randomly stopping and refusing to load pages while my Tor browser (for facebook,etc) continues to work as normal. Sometimes Skype is affected but I'm not sure if it's directly related. If i reconnect the cable then it starts working again for a short time.
This has only started happening recently. If had problems with it last week but that was because AVG decided to block any connections to either of my adapters...
I think it may be related to the DNS but i'm not really to sure.
If you have any idea what's causing this and even better a solution be expecting a cookie in the post
Thanks

It may help to reset Winsock for windows 7. This is sometimes required if TCP/IP gets corrupted.

1. Click start, type cmd in the Start Search box, right-click cmd.exe, click Run as administrator, and then press Continue.

2. Type netsh winsock reset at the command prompt, and then press ENTER.

Note If the command is typed incorrectly, you will receive an error message. Type the command again. When the command is completed successfully, a confirmation appears, followed by a new command prompt. Then, go to step 3.

3. Type exit, and then press ENTER. You should be prompted to reboot, if not you should reboot and test.

You can change to a different DNS server by going into your routers set up page and making the changes there.
Google's DNS work good. 8.8.8.8 and 8.8.4.4

If you can post a screen shot of your ipconfig/all after making these changes it might be helpful.

I'm getting netsh recognised as an internal or external command...
I'm connected to my home wireless now but i'll upload more details when im back on the server on monday