If you have touched DOS before, you might still remember what this old school command subst is all about. It’s a command used for substituting local paths on physical and logical drives, known as virtual drives. For example, if you want to have a logical drive P: mapped to a local folder on your computer, say c:\temp, you can simply use the following command to make it.
subst p: c:\temp
It’s very useful when you test out the application that uses a network mapped drive so you can have a complete test environment right on your local machine.
However, any subst’d virtual drivers are not persistent. You have to Subst them again once the computer is rebooted. Making a batch file that includes subst commands in it and placing it in startup folder doesn’t seem to be working for something.
If you want to make them like a permanent driver that doesn’t disappear, you can either
Create a new registry entry â€œstring valueâ€ in the following key:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\DOS Devices
The name of the entry should be â€œX:â€ where X is the drive letter you want to make.
And the value of the entry should be the local path in the form of: \??\c:\path. Make sure reboot once to make the change take effect.
Or, if you are not comfortable with playing around the registry keys, you can also use a tool called psubst with an option /p as well.