To make it persistent (to survive logins and reboots), you need to modify the registry. Add a string (REG_SZ) value to:

HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\DOS Devices

Set the name of the value to the drive letter (e.g. M:), and the data to:

\??\C:\folder\subfolder

This PowerShell one-liner will do that for you:

Set-ItemProperty ‘HKLM:\SYSTEM\CurrentControlSet\Control\Session Manager\DOS Devices’ -name “M:” -value ‘\??\C:\folder\subfolder’

According to some articles on Web, the drive letter should be immediately available to you, but when I’ve tested it, a restart was required to make it available to all users.

Btw, to mount local folder as PowerShell drive:

New-PSDrive -name scripts -psprovider FileSystem -root ‘C:\Documents and Settings\username\My Documents\WindowsPowerShell\Scripts’

cd scripts:

This also works for UNC path:

New-PSDrive -name N -psprovider FileSystem -root ‘\\server\share’

cd N:

PowerShell drives are visible only in PowerShell session. If you want some virtual drives to be available every time you work in PowerShell, add a command to your profile.