Yesterday I installed Mint 13, Xubuntu 12.04 and Netrunner 12.12 (I think) and everything was fine with each OS.
But 2 hours ago I installed Windows Vista Ultimate x64 on drive C (don;'t worry, I formatted the drive as NTFS from within Linux beforehand, using gparted) and now, after finishing installing the mobo, video, sound, etc drivers and restarting the machine Linux doesn't show up anymore as an option at boot start. The PC logs onto Windows automatically
Please help! I don't know how to fix the bootloader and I don't feel like wasting 4-5 more hours re-installing each version of Linux all over again and customizing everything.