computer fries - part 2

So, the new computer is great. I got my part salvage the old hard drive, but it didn't work. Apparently the part didn't have enough power to run a 40 GB hard drive (only up to 30GB). So I put the other computer back together. It so happens that while a friend was helping us move some furniture, I decided to show him how dead the old computer really was. So I turned it on, at it started up as if nothing was wrong. I spent a day tinkering with it and there seems to be absolutely no problem with it! Which was good, because then I burned all of our useful data onto 2 DVD's so we could transfer them to the new computer much easier. So, now we have 3 computers in our house! I might sell the old one to my parents for my sister's graduation present, but I'm still afraid it will crash again..... TS