cNet has lots of software that you can download.  I always get the FREEsoftware.  My two favorite downloads have been cCleaner and AVG virus scan.

I dowloaded cCleaner to help my coomputer run more efficiently.  This software can clean out the cookies and the cache as well as a lot of other things that slow you down.  It is easy to run and very fast.

I also downloaded AVG Virus Scan for FREE.  This software actually runs a full virus scan on my whole computer and lets me know if there are any problems.  This scan does take a long time...so I suggest you schedule it at a time when you will...