Internet slow after sp2 and in particular after automatic windows update

I installed sp2 a while ago and experienced a minor slow down on my computer. February 10 I recieved some automatic updates and after this day my internet has become so slow, that it cannot open simple pages, and live web casts... forget it. I am very dependant on being able to watch web casts at the moment, so it is a huge problem. At the same time my firewall was turned off and I was unable to start it again.

 

Anyone with same experience?

 

I have tried the following WITHOUT results:

 

Uninstalled sp2 (according to Microsoft guidelines) (could not open Outlook and Windows Media Player)

Uninstalled hotfix updates (followin Microsoft guidelines) (made my computer unable to start XP, had to repair XP with repair disk)

Download spyware program ControlSpy (found 17 spyware files!, quarentined them, but still equally slow)

Reinstall my processor driver (as I read that there was a problem on some Dell computers with that after downloading sp2)

 

I have after this reinstalled all the updates and the sp2 pack (to make outlook work again) and am now back to square one.

 

I have all along had an antivirus program (Symantec Norton with live updates)

 

Any suggestions on that I might try?

 

Computer details:

Dimension DIM4550

Intel Pentium 4 CPU 2.40 GHz, 512 Mb RAM

Internet connection: 3.3 Mbps (no problems at ISP)