“your system is infected with dangerous virus”

okay, so somehow i ended up getting a "virus" that causes this. it's not when i click that folder. it happens randomly. like, it will randomly popup when i go into "my documents" or "program files". it even happened when i was uploading new pictures i took to my desktop.

also, if that image is too fuzzy, i took a screencap of the popup:
image

this is getting very annoying. i've ran avg, antimalware, and superantispyware and it's still coming up. can someone please help me out? i run two domains and i'm afraid to upload new layouts to them because of this.

i thank you for any all help you can give me :D