No Projects in IDL Workbench

QUESTION: I've installed IDL 7 on my Windows computer and everything appeared normal, but for some reason, no matter what I do, or how I do it, I cannot create a project in my IDL workspace. I'm going a little bit nuts here. Can you help?

Oh, there was one error, that I didn't thing too much about. Maybe this is a clue. When I start the IDL Workbench, I get this error:

% Attempt to call undefined procedure/function: 'GMEM_MAP'.
% Execution halted at: $MAIN$
% Attempt to call undefined procedure/function: 'GMEM_UNMAP'.
% Execution halted at: $MAIN$

ANSWER: This clue was the key Mike Galloy needed to unlock this mystery for our poor IDL user. You can read the entire saga in this IDL Newsgroup thread, which was continued in this thread.

The problem boiled down to this. The user had installed IDL 7 on a machine that had a previous IDL 6.3 installation on it. In that previous installation, the user had defined the environment variable IDL_DLM_PATH. As it happened, Mike Galloy had received similar errors when he tried to use PREF_SET to set the IDL_DLM_PATH environment variable. The user found that by simply unsetting this environment variable, he could now create as many projects as he liked in his IDL workspace!

On a Windows machine, you can find your environment variables by right clicking on your My Computer icon, selecting the Properties selection at the bottom of the pop-up menu, then finding the Advanced tab in the System Properties dialog. Find the Environment Variables button on this tab, and you will get the Enviroment Variables dialog to pop-up. Find the IDL_DLM_PATH variable in one or the other of these lists and delete it. (See the figure below.)

Deleting environment variables in Windows.