Pop up question

I know this question must have come up on the bbs many times before but I need some help. When I click on MS Explorer a message comes up "if your CD-Rom door has opened you are subject to someone browsing your computer," etc and my CD-rom door does open. When I click to get rid of this a pop up a stopper ad page comes up advertising a product to stop pop up ads. When I click on this of course a ad page comes up inviting me to list credit card numbers addresses, etc. Of course I will not enter any of the requested information. I've got a pop-up stopper shareware program by panicware.com. But it will not stop the mess. I've got McAfee Virus and it's up to date. Help, what has infected my computer and how do I get rid of it, is there a shareware program available to squash it?

I believe the address displayed in the browser window is default-homepage-network.com/2929

Thanks, any help would be appreciated.

PS when the process begins it is accompanied by a "oh oh" sound.

 

Do you have Spybot and AdAware? See this thread for links and configuration.

 

Thanks, your suggestions cleared up the problems

 

Great!