Slow winXP

Hi all,
can someone help me with my problem ? I have recently installed http://www.uvnc.com/download/index.html an ultra vnc client. I was using for a short time. After i have uninstalled it my windows went crazy. IT has a major problem with cpu usage. For example the only game which i have is worms armageddon, and they run like a turtle. The game is very old my cpu is 2.6 celeron so why are they running so slow if before installing VNC it was all ok. What drives me crazy is that im using guitar pro software. When (as i used to) i'm trying to run some FX simulation program for guitar , the guitar pro acts as a trutle , after 5 seconds it goes down. I have scanned my pc for any spyware/malware/viruses ... nothing was found and pc is still running like turtle. Did u experienced something like that before?
Any ideas ?

Thanks for fast response,
ps. Merry Christmas to all