I do use a generator in my RV, an Onan Microlite. The generator does surge slightly when it is under a light load, but it settles down when about half loaded. The surging is noticable simply by watching the ceiling lights, I can see them dim.

My laptop runs just fine from it, although laptops are buffered by the built in battery. Like others have said, I would suggest a UPS, especially if it is in a business situation where the computer is mission critical. It takes time when the power goes out for an autostarting generator to fire up and reach a stable operating speed. If it's like my Microlite, the circutry prevents output for about 60-90 seconds until the speed is stable. Then the circut is turned on for use.