Boot up screwed up

[Madmullen]

This is my current spec:
Case:Corsair Osbidian 750D
Motherboard:Asrock 990FX Extreme4
CPU: Amd FX(tm)6300 six core Black Edition 3.5MHZ (now aat 3762.28Ghz)
Ram:Corsair Vengence 16GB Dual Channel @ 1600MHZ
Graphics: MSI GeForce GTX 760 OC Gaming Edition 2048MB GDDR5 PCI-Express
Sound: Onbrd
HDD: Baracuda 1TB
HDD: Toshiba 250GB
DVD: LG Lightscribe
PSU: Corsiar RM Series 650W
Aerocool X-Vision 5 Channel LCD Fan Controller

Cooling: Corsair Hydro H105 running in Push
Corsair 2XSP120mm
1 x SP120mm Exhaust
2 x SP140mm Intake

Lately I`ve been getting stuttering when playing games, so I thought the CPU could be Bottlenecking, I had purchased the board with a 5% overclock but had it running at stock so I set the OC in the bios to 5% and saved the setting all was well booted to windows fine.
Shut and rebooted but boot screen came up with multi menus stating that I had a boot failure and must press F2 or Del to reconfigure board, F11 to choice boot menu and a few others it also gave me a count down of 10secs.
If I didnt choice it was going to load the UEFI default bios setting, which it did and loaded Win7 CPU running at 3.4MHZ.
Tried another boot and managed to get F11 to work so I could choice HDD to boot from but although OC setting show in bios they do not Boot into windows.
I have also cleared the cmos reloaded the saved bios settings set up by Overclockers but still the same.
Anytime I reboot the same menu will appear.
Any help would be appreciated as this is driving me nuts.

[Madmullen]

I have managed to fix the boot problem that turn out to be a corrupt MBR which I fixed with Paragon.
But still have the problem with the stuttering.

[Tweakurr]

What driver for the 760 are you using and how long have you had the card?

Some of the overclocked cards are pushed too far and don't last. One of my EVGA 760's was bad right out of the box. It was replace right away and my SLI system is running super smooth.

[Madmullen]

Ive had the card 3 days, I have found the problem is with my CPU so I have OC it a bit to 3.7Ghz but I`ve been told I really need to get it up to 4Ghz but Im not that good at OCing.
Had it running at 3.8 but failed primr95 after an hour always seems to be core5. So I have left it for now at 3.7

[Tweakurr]

I would stress it in gaming with stock settings just to be sure.

As far as overclocking your cpu, there are so many variables. What I would do if your not sure is google "overclocking amd fx 6300" and look for those whose post their settings even if not your board. I see there are even videos out there. The voltage level will be the main factor.