[SOLVED] My PC restarts whenever I start a game

[HellsGuardian150205]

I have a very old PC (My dad built it in 2001). Now, I'm the only one who uses it. Recently when I booted up the PC, it seemed to be working properly. However, as soon as I start a game, my PC reboots. My dad thought that the problem is with the graphics card. So I removed the card and tried to boot the PC. It works fine however I can't play most of my games. Is there anyway that I can still use the graphics card?

The graphics card is a GeForce GT 710

 

[RARRAF]

A power supply has a limited life usually less than 5 years and that will be your problem get a new PSU

 

[HellsGuardian150205]

A power supply has a limited life usually less than 5 years and that will be your problem get a new PSU

Well then, I'm getting bored in quarantine.