Laptop Randomly Restart HP Hdx-18

Sorry if this was a double post I just wasnt sure which section to post it in

Hey guys,

A friend of mine who doesn't know very much at all about computers asked me for help with his laptop and since I don't know much myself but alot more than him I figured I would ask you guys. He has an HP htx-18 laptop and I don't have the specs and he doesn't know them himself. The laptop will boot up but after maybe 5-10min it will shut itself down. I looked at the event log and it had Naupdate service hung report listed in there 30 times so I'm assuming that is the error. He said he had issues with it and had brought it to a computer place somewhere in brooklyn and they told him they replaced the original hard drive. He also had the original charger cord get destroyed by his dog so he was using his sisters dell power cord which didn't have the correct voltage or amperage as the original. He now has an original power cord for his computer that he is using. What would you guys recommend I do for him because it is a fairly expensive computer that is just junk right now. Thanks alot!