virtualbox.org

So, I was booting Mac OS X 10.9 Mavs and I am getting an error:
The instruction at 0xf21e4927 referenced memory 0x00000080. The memory could not be read.

May I please have help? Thank you guys!

If you are on the correct forum (Windows hosts), you are using the wrong guest (Mac). The answer is in the FAQ: Mac OS X guest on a Windows Host.