Need help removing an ad pop-up

For the past week, I have been geting this pop-up every so often I use IE7. Some Asian site http://www.100x10000.com/cai_union.html keeps opening every time I start IE or it sometimes opens when I go to another site. I'm using XP and IE7, I don't want suggestions on using other browsers, just need someone to help me remove it. I had a similar thing a long time ago, and I searched it on google and found the solutions right away. I can't find anything on that ad, but I'm pretty sure I can solve it the same way, but I don't remember what file I deleted the first time to get rid of the other add pop-up.

I would also try the following:

1) Make sure no rogue entries have been added to your hosts file
C:\Windows\System32\drivers\etc

2) Check your DNS settings have not been changed:
"Go to Control Panel, Network and Dial-Up connections.
Local Area Connection, Properties
Double click Internet Protocol (TCP/IP)
Tick Obtain DNS address automatically"

3) Set IE back to the default settings
Click me !

Good luck !

Firefox is well worth the effort.

You might try installing a Host Intrusion Detection System (HIPS) that will make you aware when any of your system files are changed. The Free Comodo Firewall has some HIPS functionality. Another 'smart' HIPS program is Cyberhawk (also free).