That board has been out for a while. It could be a good idea to update the bios. Also check the OCZ site and see if there is any updated firmware for the drive. The Vertex was problematic when released ( I have one). The firmware updates were to correct the problems. I asked some of those questions because if you can go to bios with no problems, it is either the hard drive, the drivers, or GPU itself. The Nvidia drivers do not load until Windows loads, which is causing you the problems. When you go into bios, the drivers have not loaded yet. Also, your bios needs to be in AHCI mode for your SSD to operate at it's full potential. Here is how to do it. AHCI : Enable in Windows 7 / Vista
When you uninstalled the old video drivers, did you uninstall the old ones first with Driver Sweeper
in safe mode? Boot into safe mode, open driver sweeper and check Nvidia display drivers only, analyze, then clean. Then boot back into windows and install the drivers you have already downloaded from the Nvidia web site (current is 306.23 I believe).
Read your owners manual it will tell you which port on your board is the first port. Some boards have it written on the right by the sata connections.