There seems to be a new virus going around, infact its now a new generation of malware called "Rogue Ware"

It gives you the following system mesage:

"System Error"
Attention a! Some dangerous virus detected in your system.
Microsoft windows XP files corrupted.
This may lead to the destruction of important files in C:\Windows.
Download protection software now.
Click ok to download the antispyware (Recommended)".

It wants you to download a so-called "IE Anti Virus", but its all a clever plot to sucker you into downloading another virus. Needless to say, I did'nt fall for that and after about 2 hours of searching I found that the only Removal Tool that succeeded in removing this sucker was:

Malwarebytes' Anti-Malware

You can download this here @ http://www.besttechie.net/tools/mbam-setup.exe

Good luck and give us some feedback here.