Persistent subst for NT-clones
Windows NT has a pretty possiblity of creation persistent SUBST drives, those will
not disapper after reboot. In addition, the subst drive letter created with this method
becomes available on erly stages of system startup. Thus, services can be started from it.
It was quite useful for me when 1 of my HDDs had unxepectedly gone. To avoid registry
modifications, re-configuring and reinstalling software, and other unplesant things,
the following was done: Data from partitions was placed to separate folders on available
disks. Then parsistent substs to these folders were created.
HOWTO create Persistent subst for NT-clones
Assume, the backup copy of drive J; is stored in C:\Backup\J folder. We wants system to
operate normally until new HDD is installed. For this purpose we need drive letter J: to point
to C:\Backup\J folder. This setting must take effect durring boot-time and must be independent
on logged in users and their rights. To do this the following steps must be followed:
- Create String value in [HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\DOS Devices]
registry key. Name of this value must correspond to the drive letter being created.
In our example, the name of value must be J: to create subst drive J.
- Set data of the value created to the path to target folder in the following format:
\??\<path to target folder>
In our example this will be \??\C:\Backup\J. Note, there must be no '\' character at
and of pathname. The only exception is where subst-disk points to root folder of some
other volume (e.g J: -> C:). In this case '\' is required.
- reboot or make the same subst from command prompt:
subst J: C:\Backup\J
Now (since 2004.02.03) you can use management utility for persistent substs.
It is allso possible to import .REG-file:
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\DOS Devices]