To be quite honest having NIS installed period causes a computer to run like junk. What I suggest you do, which would speed up your computer alot is to uninstall NIS (basically everything related to Symantec (including LiveReg & LiveUpdate) in Add/Remove Programs). I would then suggest that you download
AVG Antivirus Free Edition and
Windows Defender. Both are great programs and both are free to use with frequent updates to the spyware and virus definitions. NIS is such a resource hog that it slows down computers alot.
If you are worried about not having a firewall, then I suggest you download either
Sygate or
Zone Alarm, both are free and are very good. You will be surprised on how much better your computer runs without NIS installed.
If you have any problems uninstalling Norton IS, please post that here and I will help you to get rid of it, if that is the course you decide to take.
Fenor