While installing windows 8.1 through Boot Camp recently I made a silly mistake where I inadvertently formatted disk1 partition (it was ~40mb in size) - you can say I was having finger trouble. However I was able to recover and proceed with the install fine. Everything works, booting into OSX 10.9 or Win 8.1, no issues at all. I even tested the Recovery HD partition and all is well there too. I'm not sure if it's a coincidence or not but I have since noticed that while in Mavericks when I got into System Pref > Startup Disk, I no longer see Macintosh HD there, just the Boot Camp disk. (see 1st pic) However, in Windows 8.1 when I launch Boot Camp control panel, there are 4 items listed under Startup Disk (see 2nd pic) - Mac HD, Recovery HD, Boot Camp and Mac OS X (I have no idea what this last one is). Is there anything I can do to fix this? Since everything is working fine I'm leery about re-installing everything. But ideally I would like to be able to set my Startup disk from within OSX. Right now I can only set it through Boot Camp within Windows 8.1.