Alcohol by itself (as in rubbing alcohol) will not cause any problems with your computer. It is in fact, an excellent cleaner for the surface of component boards. However, the alcohol must be allowed to completely evaporate before power is re-applied to the board, as alcohol conducts electricity. Also, alcohol (NOT rubbing or denatured, the stuff you actually drink) if spread on your computer will cause HUGE problems; not the alcohol itself, but the impurities and/or mixers in it. These impurities will often leave a conductive residue on the surface of your board and cause short-circuits and component failure.