|If you ping your ISPs gateway, what pings (ms) did you get, when nothing else is running and no one surfes the internet?|
If the ping time is also that high, you have to contact your ISP.
I had that problem in the past, where my ISP said, there was another customer also switched to my account.
The original poster should always write the last response !!!
Let us know, if the problem is solved !!!