Xp clean install -high cpu-lots of little problems

I have an hp pavillion 521n w/athlon 1600 + 1.40gz,376 mb ram.I try running a few programs(pages) and my cpu usage shoots thru the moon.sometimes it does this while I just sitting there reading somthing.Insted of switching screens,it does the old screen "peel down" because the comp's at 100%.

I recently reformatted c: and did a clean xp pro(legal) install,and for the first time I updated to sp2.Could THAT be the problem?

 

Did you also install ALL drivers for your HP? Including chipset drivers, audio drivers, and video drivers found off the HP site?

 

No I did not....I'll try that immediately.Thank You!

 

I posted above your answer thefool....sorry.