When Windows completely refuses to boot, what startup repair methods have you found most effective? I'm talking about situations where even safe mode doesn't work. What's your step-by-step approach? Do you prefer using Windows built-in startup repair methods or third-party tools? And how do you decide when it's time to move from startup repair to more drastic measures like reinstalling the OS?
When Windows won't boot at all, my first startup repair method is trying to get into Windows Recovery Environment. If you can't access it from the boot menu, you'll need installation media. Once in recovery, I try the automatic startup repair first. If that fails, I move to command prompt and use bootrec commands. /fixmbr, /fixboot, and /rebuildbcd in that order often fix boot issues.
I've found that many startup repair methods fail because people don't use the right installation media. Make sure your USB or DVD matches your Windows version and architecture (32-bit vs 64-bit). Also, sometimes you need to try startup repair multiple times. Weird, I know, but I've seen cases where the third attempt works when the first two failed.
For really stubborn cases where standard startup repair methods don't work, I use third-party tools. Medicat USB has amazing tools for boot repair. Sometimes you need to manually rebuild the BCD store using bcdedit commands. This is more advanced but gives you complete control. Also, checking disk partitions with diskpart can reveal if the system partition is missing or corrupted.