Ok, this is weird! (to me at least). Got everything running nicely, OS, drivers, Everest etc. loaded no problem, time to start OC'ing....or so I thought! First attempt was mild and as it was "verifying DMI pool data" (update success) it came up BOOTMGR is missing!!....what the hell just happened??

....and how do I get bootmgr back?...I think I've done it before but I'll be damned if I remember how.
Any help would be GREATLY appreciated, thanks