does startup repair even exist on 8 and later? i'm pretty sure they replaced it with the godawful startup repair that windows 7 had when you shut the computer down during startup.
if you have windows 7, by all means create or use an existing disk and do it but i'm pretty sure it doesn't exist on 8 and later.
if you're on 8 or later, spam f8 OR shift + f8
you should get to the troubleshoot screen, click on advanced options (if that doesn't exist it should be under try something else, just look around) and click on automatic repair, pretty sure it was designed for situations like this.
