In general, the hard disk can get slow if you don't have much diskspace.
Some program not recognized by an antivirus might try to do "weird" activities. for instance, some spyware might try to send information over the Internet. Spyware is not detected by antivirus programs. Get the free download at
www.adaware.de. Detailed information about spyware available at
http://grc.com.
Hilmar.
Difference in opinions hath cost many millions of lives: for instance, whether flesh be bread, or bread be flesh; whether whistling be a vice or a virtue; whether it be better to kiss a post, or throw it into the fire... (from Gulliver's Travels)