Slow Computer

It may well be some form of virus or spy-ware.

It may also be that you have too many applications running at once eg. lots of tool-bars and instant message type programs.

It can also happen on graphic intensive applications.

You should rule out nasty stuff first using the program below.

MBAM !

For a free one its pretty darned good !

From a CLEAN computer download and put on a flash drive.

Copy to your DESKTOP on the suspect computer.

Run it but don't change any options just use what it offers.

When its done let it clean anything it finds.
Continued use may require purchase.

Its where I always start with an infected machine.

As for anti-virus AVOID Norton or Mcafee but try the AVG FREE version

As for too many applications that would be up to you to decide what you REALLY need and don't.
Most tool-bars are a waste of both time and space and can hog computers down. Maybe a good clean up is in order ?

It may just be a"leaking application"

These are badly coded programs that don't release memory when they should and just keep taking more to do the same job.

May I suggest you also download "hijackthis"

It is a program that can make a report on what you have running in such a way that you can post that information to certain sites and experts there will look at it.

They will then give you recommendations as to how you can remove programs or fix some issues that may be upsetting your computer.

Don't post the log here but follow the instructions and help the program offers to send it to one of the sites it will offer you.

If you understand startup lists you may even be able to spot some things yourself that you don't want to run and disable them from hijack this.

In some cases you may just be trying to push your computer too hard with the resources it has.

Trying to edit large graphics files or videos with limited ram or CPU power will slow most computers to a crawl.