Computer fails to boot up!

As you can see in my video link below it lights up twice and then the dr_mos alarm on my mis m power z77 motherobard appears and it shuts down.

This is my first computer build I have no idea what to do. all suggestions will be great.

https://www.dropbox.com/s/o26s1kof5hnnkj4/20130425_184532.mp4

Can you tell me the exact specs of every part in your build?

CPU- Intel Core i5-3570K 3.4GHz Quad-Core Processor

Motherboard- MSI Z77 MPOWER ATX LGA1155 Motherboard

Ram- Corsair Vengeance LP 16GB (2 x 8GB) DDR3-1600 Memory

SSD- Samsung 840 Pro Series 128GB 2.5" Solid State Disk

Hard Drive - Toshiba 2TB

Case - Cooler Master Storm Stryker (White) ATX Full Tower Case

GPU - Gigabyte geforce 550ti

 PSU- NZXT HALE 90 650W GOLD

Psu?

The same thing happened to me on my first build, the problem for me was my CPU arrow wasn't lined up with the little arrow on the socket on the mobo.

editied my reply post Hale 90 650W

Fixed the problem. I was thinking it was something to do with my psu so looked at all my cables and I had 2 not connected. It's a mistake for a first timer. thanks again guys for trying to help