Suggestions on best way to proceed

My computer has worked fine for over a year since I built it with friends. I took a video of what is going wrong with my computer (try and listen for the click when the computer restarts):


https://www.youtube.com/watch?v=WfjPigivPjg


Whenever this happens, you can hear, the computer keeps running when it restarts and just repeats this process every time I try and log on. Once and awhile this flash will happen WHILE the computer boots up but I still can't make it past log in.

I have tried running it in safe mode and safe mode works fine. I transport my computer to friend's houses often and so I went through the process of making sure each part was seated correctly. I have done a system restore and I have tried taking out one ram stick on a time.

I am really worried that it might be a problem with my graphics card. I definitely don't know for sure though. One friend suggested I try putting the windows disk in to do a repair that way. I left my windows disk at a DIFFERENT friends house. I am taking my computer to THAT friend's house (the one where I left the windows 7 disk at) later to work on it.

What are some things I should try besides this? SUGGESTIONS!? Please and thank you. : /