Hi guys,

So this afternoon I started cleaning out some old files and eventually decided to format my secondary 160GB HDD as I was originally just using it to test out the consumer preview of Windows 8, whereas my main HDD was recently upgraded from Windows 7 to Windows 8. 

Anyway unfortunately I can't remember exactly what I was doing before this happened but at one point I restarted my computer (which is set to boot into my main HDD) and half way through the boot I get the "BOOTMGR is missing Press Ctrl Alt Del to restart" message. 
Now this seems to be a fairly common message but I've never personally seen it before. Anyway after this my computer would no longer boot up into either of my OS's. 

I've since tried several different options such as resetting the BIOS and using a recovery flash drive to try and repair the problem but whenever I use the flash drive to try any sort of repair I get a message saying 
"The drive where Windows is installed is locked. Unlock the drive and try again." 
and unfortunately I don't have a clue what it means by this... eventually I somehow managed to get my main HDD to boot into Windows 8 by ordering the 160GB HDD to boot first which would then give me a choice of OS's to boot (originally this didn't work, so again, I'm not exactly sure what caused this to change). 

If I remove the 160GB HDD from the system though I end up right back at square one so it looks as though my system is using the bootmgr files from the 160GB HDD to start the process and from there let me boot into my main OS. 

Does anyone have any ideas as to how I could fix this so that my main HDD with my main OS isn't relying on the smaller 160GB HDD for some of these vital Windows files? Would i just be as simple as copying the bootmgr files from the smaller HDD to my main one or would there be more to it than that?

Thanks