You can go into the BIOS and just change the frequency of the RAM. If it is too fast for the CPU (Not the Mobo, or both) then it should work. Look up the supported fequency of your CPU and Mobo. If you cannot get to this information, just go to 1600 MHz, and if that doesn't work go for 1333. If 1333 doesn't work, you might just have bad RAM. Which you could test by using a program called MemTest.
Alright, I went into my BIOS and saw that my RAM was clocked at only 1333 MHz, even though it's 1866 MHz RAM. I found this odd, but decided to bring it down to 1066, since I know my mobo supports that. The freeze still happened, so I just reset it to default.
So this brings me to another question, was my RAM never even clocked at 1866? Could I have changed something else when i went into the BIOS? Thanks for your help