I have a dell Inspiron 530S and it will not start. I recently bought a Dell Deminsion that is older. I already bought a upgrade kit from Best buy but it does not work with the older computer. Trying to get something off the hard drive I need. Will any power supply work or do I need a certain model? How will I know which one to buy that will work with my computer? Don't want to waste anymore money. Any ideas??? Thanks!