my pc restarts/shutdown automatically

[Arif Hassan]

My pc restarts/shutdown automatically
It sometime restarts or shutdown automatically
It mostly restarts/shutdown while playing games or sometime when windows is booting
I installed windows many times but the problem still occur
I am using old psu that is 3-4 year old 450 watts which is for Pentium 4
I have not overclocked my any components of pc yet
My specs are
Gigabyte ga-78lmt-s2
Amd fx 4300
Asus nvidia gt610 2 gb
4 gb ram 2x2
500gb harddisk
I dvd drive
This problem is not before two 3 weeks sometimes it not restarts/shutdown for many hours but sometimes it occur

 

[Arif Hassan]

Thank you for answering me
So which psu should i choose for my system

 

[Arif Hassan]

Can a weak psu will damage my pc components
Please reply
Thanks in advance