uhm, no, i am already using the latest

Are these screens captures using the PrtScn button, or another capture program? If so, then it's not your monitor that's doing it. Though you can double check it by swapping in another monitor to double check. Assuming that these are screen captures, then it's the signal coming out of your video card. Which could be some combination of one or more of the following; win7, the game, the driver, the video card. You might be able to address this issue using an older nVidia driver.

OR - I just thought of something!- check your Display Properties, in the Settings tab, the Color quality drop down of Win 7. If it's set to something lower than "Highest (32 bit)" or "Medium (16 bit)", then it might look weird like this. Because it's using a restricted color pallette. I think there is an option for 256 colors. I sort of recall having something like this back when I used Win 95/98. But it's easy to change.

the screenshots are taken with printscrn , the only way to solve this issue under windows 7 is installing older drivers 320.49, but these doesn't support g-sync at all

Do the affected games all predate DirectX 10? You could try installing one of the DX9 drivers (9.0d was the "best" available, I think, but 9.0c is still floating around), then reinstalling your NV software.

You might have to look for fixes for each game title - old games often have unofficial updates, patches, hacks, mods, etc which ensure they can run on modern operating systems. If it's not a gamed owned by Blizzard or Steam or Hasbro then there's no convenient one-stop central database, alas - although certain genres and abandonwares and fansites will tend to collect relevant material. Chances are someone else is playing whatever game you're playing on the same hardware with the same problems, as often as not somebody shares a solution.

In a VM or sandbox or isolated user account (or DOSBox emulator), if you can, to reduce the chance of breaking any other graphics/games. Installing mix-and-match DirectX components under the radar could cause unpredictable gaming issues, lol.