Why am I getting an error message on my lock screen?

[Windows Central Question]

Windows 10 Technical Preview Start up problem

So I installed Windows 10, and the lock screen shows up and a box saying "The instruction at 0x6377645a referenced memory at 0x00000008. The memory could not be written. Click on Ok to terminate the program." And whenever I press ok the screen goes black and flashes between black and purple please help!