Use the "virtual optical drive" that comes with Windows XP

Do you know that there is a relatively safe, convenient and efficient virtual CD-ROM software in the windows that you deal with every day? Then he is a pure dos command subst, its usage is: subst drive letter: path (to virtual path) Example: subst h: e:\\english.
After such a setting, then the h disk corresponds to the file under e:\\english. However, every time you start your computer, all the "virtual optical drives" will disappear without a trace. This is where you can edit the Autoexec.bat file to fix it. (under win98).
But in win2000 and xp slightly troublesome, in addition to the above command to enter the registry, locate the hkey_local_machine\\software\\windows\\currentversion\ un key value, create a new word value. Any name, the key value is "c:\\autoexec.bat" and then log out or restart the computer.
The last thing to note is that the subst command is only valid for folders, that is, it cannot handle the virtual files of the virtual CD-ROM files in iso, fcd, etc., and is invalid for some encrypted discs.
Then finally tell everyone to delete him is: subst your virtual drive letter: /d.