I'd previously read that Microsoft is offering no charge support for setup of Service Pack 2. Here is where you can find the telephone numbers for your area (be aware long distance charges may apply, depending on location).
Go to this MS website
http://support.microsoft.com/default.aspx?scid=sz;[ln];top
Select
"Windows XP Service Pack 2 (SP2)" from the drop-down list. Then press Continue.
The page displayed will show email, chat, and telephone support options. The phone number for your area will be displayed.
The number in US/Canada is 888-SP2-HELP.
The number in the UK is 0845 0902025.
N.B. Phone contact may experience long hold times. They encourage indivual chat support.
Thank you to Gilgame5h for pointing this out.
~Maurice Naggar
MS MVP