avgfree??

iv noticed avg is slowing my pc down a lot more than it used to, is this because its just been made more effective so gets busy more often? i'm wondering if i should use a different antivirus, it starts doing things even when im not connected to th internet & gets in the way of what im doing & i can hear my computer really struggling.

 

thanks Dom, i did uncheck 'toolbar' when i installed it but probably not 'Link Scanner' so i'll re-install it. My pc is a few years old but not terrible spec;
windows xp version 2002 service pack 3
AMD athlon 64 3000+
512 MB DDR

On startup:
i don't know what half of them are so iv taken a snapshot & these 5 are also listed;
acme.PCHButton
MsnMsgr
MSMSGS
BgMonitor
ctfmon.exe

I'll be adding Malwarebytes' Anti-Malware if i get this sorted, i will go though the maintenance steps when i get a chance, hopefully tomorrow.