Just a note. If anyone reading this thread is honestly concered that they might have downloaded child porn.
#1. Remove your PC's harddrive. Do not try to Fdisk, reformatt etc.
#2. Go buy a new harddrive and start from scratch with a new OS install.
#3. Call any credit cards you used to pay for that site, report them stolen BEFORE the sign-up date of the website.
#4. Never mention ANYTHING about it to anyone.
#5. No longer visit ANY porn site, adult book shop, etc.. EVER.
Granted this is a worst case issue.. but if you really are suspect.. that's the advice.
Jay