A ramble about my experience with the hated error message. I tried googling for the solution, but I couldn't find anything. That being said, I didn't expect to find anything, as we have had a laptop in our office for a couple of months without being able to fix it. Long story short, when boot manager goes missing, you're fucked, and all your data are belongs to nobody unless you have an external HDD reader to retrieve your files. Reinstall Windows. Or whatever you want, for that matter. I don't know what else to tell you. If anyone DO know a way to solve this without a clean install, let me know!
Tech fanatic Kindiz at your ... service? Watch me F### things up with my awesome DIY editions of actual hardware handling!!