So I was wondering if I'm going to have a problem playing Fallout 1 and Fallout 2 on windows 7 if I buy it via steam.

I remember some time ago people complained that it is made for windows 7 and thus doesn't play properly or the screen is extremely blurry and the colors are wrong and the game is unplayable. Is that true if I buy it off steam? How do I fix that if it is a problem?

The games come with the Hi Res patch so no graphic weirdness. However, you can always apply the Hi Res patch yourself if it does not.

I don't have them on Steam but at least GoG-versions work just fine on my Win 7. Steam-versions now have highres patches by default so it shouldn't be any issue.