Ok, I think we're confused, are you attempting to fix "BOOTMGR is missing" or are you wiping everything and reinstalling windows, I thing everyones confused here
We don't know what that 500mb iso is. Might be one the things Mahmoud is selling. If so, they are Linux, but they do have some repair functions not too dissimilar from those found in winre.
Hey all...sorry I have been MIA. So, success! I have fixed my PC!
So everyone is on the same page: I was getting the Bootmgr error on startup. I no longer have the recovery disc, so I had to download the .ios file onto a USB (I didn't have a blank disc) using Bootcamp Assistant on my Mac. I plugged in the drive onto my PC and had it boot from there. The start up repair selection wasn't fixing my problem, so I had to type in these commands on the cmd prompt:
bootrec.exe /fixmbr
bootrec.exe /fixboot (may return an ‘Eliment not found’ message)
bootrec.exe /RebuildBcd