Pc crashes

computer specs in signature.

Hardware mods from stock:
Hard drive has been replaced due to failure abt 2 years ago, graphics card upgraded , 3 gigs of ram added for total of 4

computer suddenly shuts off then reboots and sometimes does this multiple times, computer is usuable afterwards but may crash at any time. after a month or so of this it will not boot up runs through boot up and stops due to missing or corrupt file.

I formatted harddrive and reinstalled everything and computer worked again but still had same crashing issues.

I have been through this cycle multiple times. Please help

ran diagnostics got code 0f00:136c ide device failed blank or no media present in optical drive

 

the error was dvd readable writable failed.

 

Have you tried removing the DVD drive and then do a startup? Could be the DVD is bad which is fecking everything up.