Someone gave me an older laptop to look at because they were having some problems, such as getting on the internet. It is a Dell Inspiron 5150. It has a Pentium 4 and Windows XP. It doesn't have a battery. I get it and get on the internet. It hasn't been on for awhile so I do Windows update and add Ad-Aware. I powered off normally and was going to run some scans the next day and it will not turn on now. There are three lights on the front and the two on the sides flash while the one in the middle does nothing. The cord looks ok, the only thing it has been plugged into is an APC backup so why would it not turn on? I don't even hear a hard drive spinning or anything. Anyone have any suggestions?

Decent Dell Inspiron. They sold a lot of those.
You need a battery in that battery cavity... working or not.
You should have BIOS A38 installed. Do you?
There were many, many changes of drivers and BIOS on that model, so it would be good to download them to another computer and save them to a cd for installation.
Without knowing more, the problem could be anything... That model had a lot of trouble with screen failures... and driver issues. But it could be as simple as a failed hard drive or failed memory module.

She got it from a program that gives refurbished programs to single mothers, so I don't think she has the money for a new battery and I don't either. I am not sure on the bios because I am getting no screen. I am so stuck on this, she only had it for one day, any other thoughts?