CPU lag problem, please help

[Angelus1]

My new computer has been running fine for a few months now but all of a sudden I'm having lag issues with everything I'm doing. From what I can tell the cpu is hitting 100% usage while doing simple things like firefox and ventrilo and lagging my entire computer to the point I can barly use it.

I have an Intel Celeron cpu 3.46GHz and 2gb of RAM, and suggestions?

 

[Rudster8161]

probably viruses, spyware, etc. start doing some scans

 

[DannyBoy1]

Also do disk cleanup and Disk defragmenter, That also helps.

 

[blackjack]

Yes a good defrag is worth a go also try this http://www.ccleaner.com/download/

 

[esa193]

what antivirus r u using?
i suggest avg free

 

[Angelus1]

I used avg already with no results...

It was REALLY sudden not like over time build up...