Those that work regularly on computers know how quickly computers accumulate content. It doesn't take long before the computer is teeming with letters, spreadsheets, photos and other electronic documents. When a specific folder needs to be repeatedly accessed that is buried deep within this complex hierarchy of folders and sub-folders, the process goes from inconvenient to outright annoying. Fortunately there are tools, like Microsoft's subst command, that can help alleviate the problem.
The subst command, which is included with Windows 95, 98 ME, 2000 and XP, can create what Microsoft calls "virtual drives" that simply point to an existing folder on the computer. For example, a virtual drive "Q:\" could point to a folder "C:\My Stuff." The virtual drive doesn't replace the actual folder - rather, it simply provides an alternate means of accessing it (an optional shortcut). In layman's terms, it means that "C:\My Stuff" and "Q:\" can be used interchangably, and either can be used to access the files in the "C:\My Stuff" folder.
The subst command must be invoked from a command line. Once activated, the program stays in effect until the computer is rebooted or when removed by the user.
For example, lets substitute the folder "C:\Documents and Settings\Jimmy\My Documents\Project 1\Files" to a drive with the letter of "F:\"
1) Click on the Start button.
2) Click Run.
3) If the computer is running Windows 95, 98, 98 or Millenium Edition (ME), type command and click OK. If it is running Windows NT4, 2000 or XP, type cmd and click OK.
4) A black box should appear with a Microsoft copyright notice at the top. Now type subst F:\ "C:\Documents and Settings\Jimmy\My Documents\Project 1\Files"
5) If the folder name you want to substitute has spaces in the path, as the example here does, the path will need to be contained within quotations.
6) Hit Enter.
Once the directions have been completed, the computer will have an "F:\" drive. If you open "My Computer" you will see that there is an "F:\" drive in addition to the "C:\" drive. This virtual drive can be used in place of the substituted folder. For example, suppose you save a file "Letter to My Friend.doc" to your new "F:\" drive. That file can be accessed via the "F:\" or "C:\Documents and Settings\Jimmy\My Documents\Project 1\Files."
Unfortunately, this drive will disappear when the computer is rebooted, and the command will have to be repeated every time the computer is started. To alleviate this problem, follow these steps:
1) Right-click the Start button and click Explore. If the computer is running Windows NT, 2000 or XP and you want this drive available for all users that login to the computer, select Explore All Users instead. A file explorer window should appear.
2) Find the Programs folder and open it (typically this means double-clicking it). Now, locate the Startup folder and open it.
3) Right click in the middle of the open window and go to New. When the New sub-menu appears, click on Shortcut.
4) A "Create new Shortcut" wizard should appear. In the box provided, type the subst command. Using the example above, type subst F:\ "C:\Documents and Settings\Jimmy\My Documents\Project 1\Files". Click Next when you are done.
5) The next screen will ask you to provide a name for the shortcut. Change the suggested name, if desired. Then click Finish.
This will ensure that the virtual drive is created every time you login to your computer. This process can be repeated as needed (perhaps you want several virtual drives).
If you no longer want a virtual drive created upon login, simply delete the shortcut and reboot. The drive will be gone for good.
Now, there are some caveats to these virtual drives.
1) Do not format a virtual drive. In the example above, if you were to format the "F:\" drive, you'd actually be formatting the "C:\" drive, because the virtual "F:\" drive points to a folder on the "C:\" drive.
2) If you perform any maintenance on the drive (scan disk, disk defragmentation), you'll be performing maintenance on the drive the substituted folder resides on. Again, in the above example, defragmenting "F:\" would actually defragment "C:\"
3) Viewing properties of a virtual drive will display the properties of the drive the substituded folder resides on. In the above example, viewing disk properties (disk usage, free space, etc) on "F:\" would actually show the properties of "C:\" and not the disk usage of the folder "C:\Documents and Settings\Jimmy\My Documents\Project 1\Files."
4) If you change the drive label to the virtual drive, you will be changing the label of the drive that the substituted folder is located on.
In short, virtual drives can be a very useful tool that can make accessing specific folders a little easier. For more information on drive substitution, search your favorite search engine for "windows subst command."
Have comments about this article, or suggestions for an additional Tech Tips article? Send an email to firstname.lastname@example.org.