It's either overheating or there is an electrical problem somewhere in the laptop that is making it shut down. I doubt reinstalling windows will do anything now.
Well I have fixed it

!Guess what it was....?The power supply

.I asked my dad how many he had & guess he has 3 for the laptop.The OEM had the tip cutoff and he couldn't find it.But the other is a rocket fish universal.Tip was cutoff,but in the box.Spliced it together,didn't solder yet.Found the right tip to fit & bam!Works perfectly now

.When I select shutdown,it logsoff in 1-2sec then shutsdown soon as you see"shutting down" lol.Very fast.
Plays music cd fine in media player,but media center keeps closing on me.
Thats all I need to fix now.
Edit:The PSU I was using,I thought it was the gateway OEM.Was wrong.It was a cheap knockoff he bought from honkong when he had to order a PSU adapter jack for the MOBO.I know I soldered it good.The seller said that PSU would work,well it does.But it doesn't have enough constant draw when doing something that needs more juice.
The cheap knockoff I was using:
IN:100-240v-1.5A(50/60hz)
Out:19V-3.16A
The rocket fish PSU universal:
IN:100-240V-2.5A(2,5A),50/60hz
Out:15-20V/5A 90W max
Figured I would post that,incase anyone runs into this problem and googles it.