help PC gtx 670 w/ OSX 10.6

help! After upgrading to Mavericks from 10.8.4, I've been getting all kinds of weird issues, most notably the system auto restarts all the time, for no apparent reason. On bootup I got a very cryptic error message, and it was happening more and more frequently. I'm assuming its a software thing cuz I had been having no problems with 10.8 for over a year, but backed up my software in case anyway. Now the real problem. Looking to see if it was really mavericks that messed up my system, I stupidly told the startup disk to load OS 10.6.8 (my old OS before I got the Nvidia gtx 670). I had completely forgot that without the BIOS on the card (or EFI, I forget), I wouldn't be able to hold "option" at the startup to reselect the proper startup disk. Since then I've had so much trouble trying to get it to boot, I had a windows boot camp partition and well and could fix the startup from there, but I can't seem to boot into windows or os 10.9, it just keeps loading up 10.6.8 with a black screen (but I know its working, I can play itunes etc through the keyboard).

Help! I tried installing 10.8 on a USB boot drive but the OS doesn't seem to see it at startup when I hold down command-option-shift-delete, is it cuz its USB and not firewire? I'm nice with Macs but I'm ****ed and really don't want to put in my old 8800 GT, I don't even know where it is. So anyone know how to force reboot into windows, or force select 10.9 or force boot OSX from a USB drive?

Let me know guys, thanks! After this I really need to flash the correct EFI/BIOS on this thing if that's out there as well..

Dave

sweetness

got it working guys thanks! ending up burning OSX 10.8 to a USB drive and made it bootable with disc utility, it loaded up by holding C at the startup and I was able to correctly select my startup disk. Fewf!

have a good sunday yall

D