Tools for boot up issues:
For any error messages about boot problems or the MBR try the following. If you suspect this is a disk error, jump straight to ChkDsk.
BootRec.exe /fixmbr
you can also substitue the /fixmbr with thes commands:
/FixBoot. Writes a boot sector onto the system partition to start Windows
/ScanOs. Scans all disks for Windows installations and displays them to you.
/RebuildBcd. Scans all disks for Windows installations and prompts you to pick the ones you want to add to the BCD.
If this doesn’t work try Booting from “Last Known Good Configuration” from the boot menu. (Tap F8 while OS is booting).
If you can’t get to last known good config, you may need to run this from CMD.
BCDEdit /SET “{bootmgr}” displaybootmenu yes
If this doesn’t work try the startup repair from the repair disk.
If the doesn’t work, try an SFC scan.
If the System is Windows 8 on wards, try DISM.
If that doesn’t work run a ChkDsk -f -r from command prompt.
One of these tools should yeild some kind of result unless there is a massive OS corruption or hardware failure.