I'm required by my employer to use Microsoft Windows as my desktop client system at work. Over 95% of my work is actually done on AIX or Linux systems, and even though I have begged for a Linux desktop system I have to use Windows because it's the "company standard".
Recenty I've been given Windows XP on a notebook system to use at home. Personally I would have prefered Windows 2000 - if I must have Windows, it's not a fast box and it doesn't have much RAM. Even after turning off all eye-candy, it's slower than my old desktop system running Debian sid. The XP box has a PIII-696 CPU and 256Mb RAM, the Debian box has a PPro-200 and 128Mb RAM.
What really shocked me was how painfully slow Outlook/Exchange is. I hate Outlook beyond description, it's probably the worst email client I've ever used. At work I'm forced to run Outlook, but it's over a LAN so I don't see how slow it is. Running mutt/Thunderbird with IMAP over my ADSL link at home is fine, running Outlook over the same link is painful, it takes minutes to start and close - it's really pathetic!