The first thing I'd do would be to run chkdsk and let it check both partitions for bad sectors. I'd also get hold of EasyBCD to examine and make any necessary changes to the BCD (Boot Configuration Data).
OK, so I built a computer. I installed Linux Mint and Windows 7. But now when I start up, sometimes the BIOS does not post it's "GIGABYTE" symbol, and when it does, when I use GRUB to choose an OS it loads the splash screen of Windows, and then the computer screen goes black, but the monitor is still getting a signal. If I load Linux Mint, it show a loading process on screen for a bit, and then goes black. And here is another weird thing: Windows has successfully loaded twice while this was happening, and Linux has loaded once. And Windows Safe Mode has not failed to load. There are so many inconsistencies. Any help with this is greatly appreciated.