Anyone else seen anything like this?

[dickthegrouch]

I have a "luminous mask" for want of a better phrase on my desktop (PC).
It shines through any window I care to put on top of it and can't be captured by cutting and pasting, or by print screen.

It looks like a white mask used by men in fancy dress balls.

I have the uncomfortable feeling that it is telling me my every keystroke is being watched but I have run Microsoft malicious software removal tool, NIS scans, Lavasoft, Spybot search and destroy, and Norton's Power Eraser. None of them have come up with anything that looks like spyware.

The mask even appears before the OS is fully loaded, which makes me think it's coming from the video driver firmware. This started about 4 days ago.

Added on edit:
MS Vista x64 on Gateway NV5602 computer

Am I just paranoid, or should I try harder to diagnose it?

TIA for any assistance you can give.

I have a very poor jpg showing roughly what it looks like (I'm no artist) but I couldn't figure out how to upload it.