5 beeps usually means a processor error. Unfortunately, this is bad news. You can check your memory cards and make sure that are all securely inserted. However, if they are and that did not fix the problem, you will need a new motherboard. Its probably time to get a new computer.
Since this is a motherboard problem and not a hard drive problem, you should be able to take the hard drive out of your old computer and get the information off of it that you want to keep.