!!!URGENT HELP NEEDED!!! Overclocking failure

[LittleBigRunner]

Hi! I was looking for some extra performance since my system is an older one, so i used the alienware profiles that they set for you. I used it once and it didn't work (clocks were still at 3.4Ghz according to cpu-z) so i tried again. I saved and exited and got greeted by a 'windows has failed to boot, probably because of a recent hardware or software change. heat is not a problem as it is extremely cold where i live thus very cold cpu and gpu temps (25 degrees celcius), and fan speeds are very high for gpu and main fans. I have tried safe mode, using last known working config, disconnecting power, and resetting bios (doesnt seem to apply, i select it, i confirm and press yes and i exit but still no luck. I looked in bios and according to it the cpu is at 3.4GHz. Please any help would be appreciated urgently.

Alienware Aurora R3 (with upgraded gpu, psu, and extra fan):
I7 2600k (3.4Ghz ._.
GTX 780 (1058) Overclocked by 100MHz
1000+ corsair psu (not sure how much watts by more than enough for sure

 

[basroil]

Reset the BIOS (unplug the computer, remove coin cell, wait a few min, put battery back in) and hope it's not that you seriously screwed up the computer.

In general, overclocking is something I would never suggest doing until you understand the risks and how to recover.

 

[beegmouse]

Bear in mind, it doesn't always matter what temperature your CPU is. If it is unstable above a certain speed, it doesn't matter what kind of cooling you have.
You typically have to up voltages to improve stability. And then improve the cooling to leech the extra heat.

Take it back to stock and see if it boots.

 

[manv]

MERGED QUESTION
Question from LittleBigRunner : "!!!URGENT HELP!!!! Overclocking failure help"

Hi! I have an older 2011 Alienware Aurora R3 system. I tried to overclock by using the overclock profiles that alienware give (alienware support even told me to use it if i wanted to overclock). I selected in the bios (profile level 2 oc), saved changes and exited. I went into windows and checked and it was still a 3.4 GHz. I tried restarting and trying again and when i selected it (not adjusting any other settings) i got a 'windows failed to start, this may be because of a recent hardware or software change). I tried doing to bios reset option but it doesnt seem to do anything. I've also tried to make sure its at stock clocks (in the bios) i've tried windows repair option (3 times), safe mode, go to last known working config, and disconnecting all power to system. Any help would be extremely appreciated. Thanks
Aurora R3 (upgraded PSU and GPU)
I7 2600k (3.4GHz ._.)
GTX 780
8GB ram

Remove your CMOS battery and wait about 10 mins then replace it and then trying to boot again.
If that that does not help Im afraid you will have to reinstall windows as repairing etc has not helped you.