So I was trying to get my Corsair Vengeance to run at its normal speed of 1866mhz instead of 1333mhz and I was told to do so you had to enable the XMP profile in your BIOS. I'm using an ASUS Sabertooth z77 by the way. So I found the XMP setting in the "advanced" section, enabled it, and now my PC won't post. The fans come on, it tries to start up, then just turns itself off after about 10 seconds.
EDIT: FIXED, just reset CMOS with the the button on the I/O panel. Thanks for the help n0c