Programs loading sooo slow

[hoursurfing]

Yesterday my computer slowed down big time. Its really only slow when I try to open a new program. It takes like 45 seconds to open up Mozilla or any browser. Every program is like that even Word.

Once the programs are up they work at decent speeds. Browsing is fine but the programs crash often now especially if I try to open too many programs.

I've done various scans and nothing comes up. Its like trying to run other programs while doing a virus scan... nothing works right.

The one thing it could possibly be is the heating fan. I noticed it turns on right when I start the computer and doesnt turn off.

What would you suggest? Ever heard of anything like this?

Thanks