Travel Technology - Maintaining mapped drives in Vista

I have been mapping a specific folder to a drive letter. I have done this both by the SUBST command line command and by the Explorer method (can't recall how). IN both cases, after either a restart or some other even the mapping is lost and I have to reinstate it manually.

Is there a way I can map it and not lose the mapping, or at least remap upon every startup automatically (in case the mapping has been lost)?

I have been mapping a specific folder to a drive letter. I have done this both by the SUBST command line commandYou can create a BATch file, containing your SUBST commands, and place it in the Startup folder.