Registry Cleaner Pop Up Window

Hi, I hope someone can help. I am running win xp sp2 home edition, and everytime I log on to the internet, I get this window that says something about Registry Cleaner, so since I dont know what it is I press the red "x" and then another window pops up and says I did not complete my registry clean. It asks do I want to continue with it, and I press no and it goes away.

 Also the strange thing what happens is when this happens, I will go to the history button, and in the column of history files, " My computer" has these files called "NDR29.tmp, NDR3c.tmp, NDR3F.tmp" and so on. I cannot figure this out.

 Does any of this mean that I may have a virus or trojan horse? I also am running Norton Anti Virus, Internet Security, AdAware SE Personal, and Spy Bot S&D, and after running all of these with up to date status on each one, it all comes back clean.

Any help with this is appreciated. As I type,  the pop up window just comes back every so often and it is so annoying. Is there any link that I could go to that can help me out, or maybe another program that can detect to see if I have virus or trojan horses?

Thanks, Joe