This suggests the the power supply (psu) is failing and needs replaced, this very well could cause the problems you are experiancing.
Another problem is the cpu temp at 65C, this is high and could also contribute to the problems.
You need to deal with the psu first, as in replace it, then see what the temps look like and go from there. We can guide you thru this if you feel comfortable working inside the computer as well as help you find a new psu.
Problem is we need to know exactly what hardware is in your computer, can you install and run Everest?
So this computer is not a dell, HP, Compaq or any other name brand?