Have you done your latest BIOS update?
Check your manufacturer's product downloads page or Intel's support downloads page for your mobo: http://downloadcenter.intel.com/Sear...OS+Independent
There are 13 BIOS updates for your board on Intel's site alone, latest 1/9/2009
But your manufacturer's updates should be given first priority.
If Startup repair doesn't repair boot issues, then consider doing a repair install which in Windows 7 is an Upgrade over itself run from desktop. It saves all programs, files and settings in place but replaces the OS and reconfigures the boot.