I played HoMM 1 a long time ago, but a remember the game less "pixelated" then the gog version, dose anyone know the best quality settings for Heroes 1 ? also is there a way to have a full screen game? without the chopped black screen on both sides?

"chopped black screen on both sides" is a good thing, since it means the game is displayed in the correct resolution on a modern monitor, without stretching.
Anyways, the game looks absolutely fine on my 22 inch monitor with the default settings. If you have some huge ass 50 inch monitor or something I don't think anything can prevent pixelation.
If you played the game back in 1995 you probably played it on a 12-14 inch monitor.

If you play a lot of older games, I would recommend getting a CRT monitor for these. You can also look through my thread about emulating such displays.

You can remove the black bars in your GPU setting, but that will stretch the game horribly out of proportion like PetrusOctavianus said.

Does the HoMM1 come on Dosbox? If yes, then you can change the scaler setting to try make it less pixelated.
http://www.dosbox.com/wiki/Scaler

Thanks for the Wiki-link Scaler:) It helps a lot.. i think i will get used to the chopped black screen. Hardly notice them when played one hour:) Thanks for the feedback:)