Windows working SLOW

My computer is working slow and when I look at the windows task manager, the cpu usage is at 100% at most of the times. This happens when I use IE. I removed a low security risk virus "cmdow", but it is still happening. I have run the full system virus scan with Norton Internet Security and Win Live One-Care, and there are no viruses present.

Core 2 Duo e6750, 2 Gb ram running XP sp3.
When it goes to 100%, it stays there and does not release the cpu. I end up & reboot to reset the computer.

Can Someone help...????

svchost.exe is not a virus. There are 6 of them, when I open the task manager (processes). It is the service provider which host the computer. You can reduce it by "msconfig" and then disable the programs that start with your computer!

Please help me with it !
its the right track where u showing mee!

Open Task Manager choose Processes then click on the cpu column twice to sort the list into descending order of usage you can then see which process is hogging the system. Some time back it was quite common to find a svchost.exe running at 99%.

Your choice of switching back from Microsoft Update to Windows Update was a correct one.

That bug in updates has now been sorted so what you should do now is rather than just reply on the background automatic updates is to:

1. Load IE and go Tools -> Windows Updates. Choose the Custom button. You'll probably get a pop up saying that essential updates are needed. Install these - they are usually the Windows Genuine Advantage and possibly an essential update to Windows. Once these have installed continue on and install ALL critical fixes and take a look at the reccommended ones too.

2. Once all of those are on and you have rebooted load IE and do a windows update again and choose the Microsoft Update option this time. Allow the ActiveX object to install and then follow the onscreen instructions. Do a Custom check again and see what fixes are required. This time there shouldn't be any fixes for Windows but there may be some for Office etc.