Firstly, thanks to all who replied, some great ideas and gave me places to look.
I need to be logical here, somewhat at least. My games crash, but it isn't a constant thing. It's annoying but I've lived with it for years now.
I really think this is motherboard or power supply related, as it's always done it.
You don't need a Z68 board because you were never overclocking and you haven't had working USB 3. I'd find an H61, H67 or P67 board. Test that and a new PSU - only needs to be 400W maximum for your parts.
After all these years I'm still being schooled. I wrongly assumed it was the more expensive boards I needed, I couldn't afford the £100+ for an old board which MIGHT fix my issue. So thanks for that information.
Since the boards I've looked at in the right price have only 2 memory slots, I will drop 8GB ram if I go down that road. Getting a 4 slot board is an option, but those are made by Foxconn and I have no idea if they are a good brand.
Moreover, if I buy a new motherboard and PSU and it does fix this issue, I wouldn't have gained too much. Does that make sense?
People buy components for their machines for a boost. I will still get the same **** poor frames in some games.
I suppose I have to weight it up:
Functioning USB ports
No more crashes (possibly).
Over the random occasional crash and one functioning USB port.
Most importantly, there is no guarantee that replacing those parts would change anything. I could play a game for hours and no issue and then a crash.
Did it crash because sometimes games just crash?
Or was is another issue. Memory? CPU?
I need a thorough upgrade and I am hoping if my finances play nice, I have a plan hopefully at the end of the year to buy an entirely new machine and I will no doubt be calling on you guys for pointers and assistance during that period.
So again, thanks for the input. I think since last night I managed to play Arma 3 with no issues, I will just put up with this annoyance until I can afford to go big or go home.