You can create 3 BATCH scripts, one for each os, and they can use the bcdedit
command to temporarily set the os to boot by using the /bootsequence
option.
How to do:
First we need to know the GUID of each os.For that execute bcdedit /v /enum ALL
and look for a "Windows Boot Loader" entry with a description which matches the os you want to get the GUID from, now the GUID is the value in "identifier".
Now create for each os one batch script containing:
bcdedit /bootsequence
shutdown -r -t 0
Replace with the GUID you got before.
Now you can boot into every windows you want by executing the BATCH scripts as admin.
Tip:
You can create a desktop shortcut to execute the script as admin by default and use a keyboard shortcut.
For that create a shortcut of each script on your desktop, open it's properties, switch to the "Shortcut" tab, now you can set a key combination under "Shortcut key" and under "Advanced..." you need to check "Run as administrator".
Security Warning:
As you execute the scripts as admin you should set strict permissions to prohibit non-admin users from editing the scripts.