Some users have experienced an inability to open Smalltalk windows accompanied by an inability to open generic Windows applications such as Notepad, this may be due to a scarcity of resources in the Windows desktop heap.

Microsoft provides a tool to monitor the desktop heap to further diagnose the problem.

Windows maintains a desktop heap. As windows are opened, that heap is depleted. When the heap is used up, no more windows can be opened. A tip that this is happening is an inability to open any XP windows (notepad, control panel, etc.).

Here is a URL to Microsoft on the topic of a Desktop Heap Monitor:

If you have difficulty installing the Desktop Heap Monitor, refer to this page from Microsoft for a possible solution: http://support.microsoft.com/kb/914216 .

After installing the Desktop Heap Monitor, you can take snapshots when Smalltalk has just been launched and when you are unable to open Smalltalk windows. The heap size should be nearly zero if this is indeed the root of the problem you are experiencing.

If the desktop heap is the source of the problem, its size can be changed by updating the Windows registry. There is a registry change that can be made to increase the size of the desktop heap on the Microsoft website if you need more windows. While Instantiations does not recommend changing the heap size, the following information on how to do it is provided by Microsoft.

For Vista: http://support.microsoft.com/kb/947246

For other Windows platforms: http://support.microsoft.com/kb/126962