I have just reinstalled my system (XP Pro SP2). Authenticated updated and all. I haven't changed any hardware and in fact I reinstalled less software than before. Since reinstallation, I've noticed considerable deterioration on scroll speed (eg in Firefox and in Word & Excel. For firefox I've checked "smooth scrolling" it's off. Especially Word used to be up to 1page/sec while scrolling with arrow keys, now is down to 5-6 sec/page. Also: normally Word shows the page numbers (lower left corner) changing as you scroll - not anymore in my case. Any ideas? I can't say whether overall performance is reduced with certainty. The 2.66GHz machine is clean according to avast antivirus, spybot, adaware & adwatch, Netscape's own spyware scanner. Reg mechanic finds not problems. HD (40GB) is error free and cleaned-up and defragmented. Thanks to anyone who could help.