Nov 15, 2013 Went into Boot Camp Control Panel on Windows 7 and Macintosh HD appear so I changed it from there. Now my rMBP boots up in OS X by default. BUT I still can't get Macintosh HD to show up on the OS X side. Not sure if this matters but my external and usb thumb drive doesn't show up either when it's connected. If you use APFS, then your macOS boot volume may not appear as a choice in the Windows Boot Camp Control Panel pane. The following procedure can be used to fix this problem. Since the Windows Boot Camp software can detect bootable 'Mac OS Extended (Journaled)' volumes, the follow instructions create such a volume.
Boot Camp Control Panel User Guide
You can set the default operating system to either macOS or Windows. The default operating system is the one you want to use when you turn on or restart your Mac.
Set the default operating system
In Windows on your Mac, click in the right side of the taskbar, click the Boot Camp icon , then choose Boot Camp Control Panel.
If a User Account Control dialog appears, click Yes.
Select the startup disk that has the default operating system you want to use.
If you want to start up using the default operating system now, click Restart. Otherwise, click OK.
You can’t change your startup volume to an external FireWire or USB drive while you’re using Windows.
Boot Camp For Mac
To learn how to change the default operating system using macOS, see Get started with Boot Camp.
Restart in macOS
In Windows on your Mac, do one of the following:
Restart using Startup Manager: Restart your Mac, then immediately press and hold the Option key. When the Startup Manager window appears, release the Option key, select your macOS startup disk, then press Return.
If you’re using a portable Mac with an external keyboard, make sure you press and hold the Option key on the built-in keyboard.
Restart using Boot Camp Control Panel: Click in the right side of the taskbar, click the Boot Camp icon , then choose Restart in macOS.
This also sets the default operating system to macOS.
Windows To Mac Os Bootcamp
For more information about restarting in macOS, see the Apple Support article Switch between Windows and macOS.