Question Refreshing Old System


Jun 8, 2011
Hello Everyone, thanks in advance for your help and suggestions. I know this is probably asked a lot, but here goes...

I have:
AMD Phenom II 965 3.2 w/Hyper 212 cooler
8 gigs Hyper X DDR 3 (2g x 4 slots)
MSI m/b ATX (AM3+)
500 watt Corsair psu
Cooler Master Cosmos II case
SSD's: WD 2tb Blue (just installed), Samsung 860 PRO 256 gig, 750 gig WD Blue 3.5 Hard Drive (probably dead never access this anymore)
Windows 10

Computer restarts randomly after installing the SSD (seems to do with power). I think I have maxed out the psu. I am wondering what you guys think about spending $200 to $300 to purchase the best processor I can get for that motherboard, and also maybe upgrade the cooling in my case? I can't afford a new $1000 build until maybe the end of next year. And you know, the whole deal with chip shortage right now making a new build being very expensive and all. Should I save the case, psu and graphics card and just upgrade the Mobo/CPU/Ram? The graphics card is very old now. Should I consider re-doing the thermal paste on it?

Also, Down the road I thought I might repurpose this PC into a home server or maybe just an extra PC for the garage or something. I play mostly older STEAM games Pillars of Eternity, Civ V, Baldur's Gate. Some Multi-tasking in Excel while running multiple programs.
A Phenom 2 X6 and a fresh windows install would be about as far as I would upgrade it. About 35 dollars on the used market.
You get 6 full cores for multitasking and performance . The SSD will make it seem like a new system if working properly with a new windows install.
My wife still uses one as a daily driver and I still have one folding with a GTX 960 4gig and 1060 6gig installed.

Except for the power supply, which we don't know the model of yet.