Right, so I bought all the right parts, I think, and put it together correctly, I think, why don´t my PC work!?
The parts I put together is:
i5-2500k stock cooling
ASUS P8Z68-V PRO
Kingston DDR3 HyperX 1600mhz 2x4gb
MSI 560ti Twin Frozr II 1gb
Corsair HX 650w
Pleztor DVD R/RW
WD Velociraptor 150 gb HDD
Here´s my first problem: When I try booting it up it gives me a CPU-temp to high error? How come? And the CPU don´t feel hot at all...
My first thought is that you haven't plugged in the CPU fan properly. Open up your computers and give all cables and wires a thorough check to make sure they are all connected properly. Also, there might be interference if you plug in the CPU heatsink fan in another connector; make sure it's plugged into the one labeled "CPU_FAN" or similar.
Yup, the CPU fan is correctly and safely plugged, and I´ve conected both PSU ocnnectors to the MB..
Just tried rebooting, and it still says the CPU is overheated right of the start.. 86 C now, but slowly dropping to 74 C...
Also, the BIOS detects my 1600 mhz RAM as 1333 mhz...
You'll have to set the speed manually or enable XMP, then it'll detect it at the faster speed, since technically you're 'overclocking' the ram since SB's natively run with 1333.
Assuming your fan and everything is connected correctly, you may have a bad sensor, and unfortunately there's not much that can be done about that, and if it's keeping you from being able to boot or do anything past the BIOS then you'll need the mobo replaced. Again, that's assuming everything is plugged in correctly, which should obviously be done first.
The stock cooler has flimsy graphite. It's easy to fuck it over. If this happens, which it seems to have in your case, simply get new thermal paste.
Remove the old graphite (120% alcohol is particularly good at it), then place a small dot of thermal paste on the processor. Place the heatsink on again and secure it. Your temperatures should drop enormously.
I know I'm coming into the thread late, but good job on fixing the problem! Glad to hear it, 26C is a great temp, even for stock cooling. Get some pics in the post your gaming setup thread when all's said and done!