Can you run a computer on generator?

Transformers have nothing to do with cleaning up a supply... in fact, in some circumstances, the inductance of a transformer could add more electrical "noise" to the original.

If you're serious about doing this, get yourself an Uninterruptible Power Supply (UPS) Even a small capacity one will do, as long as it has the power handling for your needs.

A UPS will take an AC from the line or your generator, and convert it to DC. This is used to charge a battery, and DC power from the battery is used, in turn, to run an inverter, which produces clean AC

Generators and other mechanical power sources usually give you very "dirty" power, they just can't respond fast enough to fluctuations.

You only have to try running your lights off one to see the variations, each time tthe fridge starts up

If the generator is producing a clean 60 Hertz and 110 - 120 V AC, you should be able to do it. However, you won't get "clean" enough from an electrical standpoint...you will have a lot of ups and downs because there is no TRANSFORMER between the source and the computer. A transformer splits the signal of 220 V AC into 110 AC and cleans the signal so it is constant within a very narrow range. Without a transformer, you get large surges up and down, spikes...and this is NOT good for a computer or any electronics. I think you can purchase a small transformer that will clean the signal, but do make sure you are actually getting 60 Hz and 110 V AC from the source. This has nothing to do with surge protection, which absorbs large spikes.