I’ve faced several of these in the past, but I’m fuzzy on my solutions, especially on win7. Rebuild mbr? Startup repair from install disk. Googling always helps, as there is no problem that someone else hasn’t solved.
Good luck!
My brother in law had this problem , I used a Linux CD to boot from and found out his Hard Drive was about to go Boom ,he didn’t listen and it went Boom and he lost all his data