I've been running Outlook 2000 and now 2002 for years on Dell machine with Windows 2K. Six months ago 2002 SP-3 started slowing down. Have tried all well-known fixes, disabling IM, setting e-mail for plain text, reinstalling, running detect and repair, Spybot, Norton Corporate Anti-virus, Housecall anti-virus and Registry First Aid. Defragged, etc. Also run Outlook add-ons Anagram and Plaxo. Have removed both, singly and together, without improvement. All other applications (Office XP suite, IE, Firefox, First Class client, AOL IM, WordPerfect 11, RoboForm, Palm Hot Sync, Chapura Key Contacts) run very well. Machine appears to be very clean. But problem is getting slowly worse.
For all of this, in many ways I understand very little how PC's work and am totally frustrated by this problem since I am heavy user of contacts & e-mail in Outlook.