Urgent! Boot issues unknown cause, finally got to boot setup, what now?

[Arvid_I]

The past 2 weeks I've had issues booting my computer, it gets stuck on bios splash screen and keyboard is unresponsive. I will list everything I've done so far trying to resolve this, and also my computer specs.

? I've tried all combinations of ram stick in slot placements (2 sticks 4 slots). In the week before this one it was able to boot with one stick, since then less and less consistently and today nothing has worked until just 5 minutes ago (hence urgent help needed)

? I tried removing the cmos battery to reset it earlier today, system managed to boot once with one ram stick and all USB devices unplugged, then back to square one the next boot (stuck on bios splash)

? During the successful boot after cmos reset i burned memtest86 to a cd. It's currently in the disk tray.

? what i did just now that got me to the screen in the picture below was try and boot with no ram stick in (obviously failed), then unplugging everything, put both ram sticks in and during startup desperatley and frustratingly spamming delete key and f11. A message showed "cpu or memory changed, press f1 to enter setup". I press it and get to the screen in the picture. I have absolutely no idea what to do now and i'm scared to death to do anything without consulting someone with more knowledge on this stuff first.

Specs: (I got this list from the company who put the computer together in 2012, i only have a vague understanding of what this all means)

MOBO: msi Z77A-GD55

RAM: Corsair XMS3 1600MHz 8GB (2sticks x 4gb) CL9

I noticed the ram sticks are 1600MHz but the bios splash screen i keep getting stuck on says 1333 MHz RAM or something, could this be the issue?

PSU: Silver Power SP - S750M 750W PSU

CPU: i5 3570k

GPU: Sapphire Radeon HD 7950

SSD: Intel 330 SSD 120GB 2.5" Sata 3.0 w/kit

HDD: WD Desktop Green 1TB SATA 3.0

Here is the screen im currently on:
imgur.com/CtPwpCV

Exactly what should I do now? Boot from the cd to run memtest86? Some other thread op with a similar issue resolvd his issue with something about XMP when talking about ram, is that something to do with 1333 mhz versus 1600 mhz?
Please help me.

Best regards,
Stressed hardware noob

 

[cin19]

Most likely it is the RAM problem, if you can boot with one stick ram, then test the RAM one by one with memtest86. I know the manufacturer will set some of ram in the lower speed like 1333mhz for the 1600mhz memory, you can manually set it to 1600mhz or use the XMP feature, and sometime it will help, because XMP will automatically set the right voltages for stable.

 

[Suztera]

The image you linked is the boot menu. It is where you choose what to boot first.
Your pc should still be capable of running fine with 1333mhz. Using a XMP profile is what will allow the ram to run at 1600mhz else natively it will default to 1333Mhz.
You can choose to run memtest86 to test the ram.

If you cannot boot into the bios with all the drives unplugged, you may have an issue with the motherboard/ram. If you can, then it may be the drives.

 

[Arvid_I]

Thank you for your responses. I cannot boot past bios splash at all no matter how many ram sticks i put in or what slot, it hasn't worked all day, now it's worked once (i got lucky?), what does enter setup do? Should i boot from SATA3 Optiarc or UEFI Optiarc to run memtest? Is that the best thing to do or should i select another option, maybe enter setup if i can change boot order from there? Any reason to do so?

 

[Arvid_I]

I clicked UEFI Optiarc and it took me to bios menu. What should be my next step? What can i do from bios that would possibly resolve the boot issue?