Is it safe to use a can of compressed air on the inside of my computer?

The ges in the can are compressed to the point they become liquid, even thought they usually evaporate before leaving the can i wouldnt worry about that, but the sparks could cause some damage, the computer must be unplugged from the wall socket and left about two minutes to discharge before cleaning (it can be also discharged by pressing the power on few times after un-plugging from the wall), otherwise the liquid or whatever else gets inside can cause short circuits, sparks and damage to computer components. Well, now that this is clear i`d just wait and see if some problems occur.