boot.exe keeps reappearing. HELP!

Okay, so. I started getting a popup everytime I access ANY webpage.
http://i4.tinypic.com/86fztkz.jpg
the enter network password pop up. If I click okay, it just comes back up. If I click cancel, the error on the right pops up.
I searched for boot.exe on my computer and there is a "boot.exe" in C:/
I tried to delete it, but a few minutes later it will reappear.
I have the Sygate S&D, and Also the lavasoft adaware free thing.
They were coming up with "Virtumonde" everytime I scanned.

I deleted it using the command prompt, and the popups stopped showing up and next time I scanned, the virtumonde thing was gone.
But next time my computer was restarted, boot.exe showed up again and now the popups are happening more frequently. I just want to get rid of this problem.
Help?!!!! :\