Hi Lodlike,
No, resetting CMOS will not wipe your Windows. And no, it probably won't make your video feed return.
Would you mind answering a few specific questions about the problem? We'll probably need to know a bit more about your setup before we can really help.
- Is this is brand new PC build that is not displaying video?
- Is this a machine that you've had for awhile that has suddenly stopped displaying video?