SUMMARY
If a second instance of Microsoft Windows 3.0 is started from another
application (including an MS-DOS virtual session, the MS-DOS Shell,
or certain Windows applications), one of the following error messages may
be displayed:
Cannot run second instance of Windows, exit this instance of
Windows and run from the original version of Windows.
Cannot run a non-Windows application from the second instance
of Windows; exit this instance of Windows and run your
application from the original instance.
Insufficient memory to run application; close one or more
applications to increase available memory and try again.
Microsoft recommends that you do not start Windows from within a shell
utility or from menu program.
NOTE: The information in this article applies to Windows 3.0 and 3.0a; it
does not apply to later versions of Windows.
MORE INFORMATION
Second Instance of Windows Started from MS-DOS Prompt
A second (or additional) instance of Windows is created if you issue the
WIN command from an application running within Windows, including the
MS-DOS prompt and MS-DOS batch files. If this happens, the following error
may be displayed:
Cannot run second instance of Windows, exit this instance of
Windows and run from the original version of Windows.
For example, if you start an MS-DOS session from the MS-DOS Prompt within
Windows,you have access to all MS-DOS commands and statements. If you then
type
WIN and press ENTER, a second instance
of Windows is started and the error message is displayed.
To end your MS-DOS session and return to Windows, type "EXIT" (without
quotation marks) and then press ENTER. To return to Windows without ending
your MS-DOS session, press ALT+TAB.
Second Instance of Windows Started from MS-DOS Shell
Although it is not recommended, you can run Windows from the MS-DOS Shell.
However, if you attempt to execute an MS-DOS application within Windows and
you have the MS-DOS Task Swapper option enabled, the following error
message may be displayed:
Cannot run a non-Windows application from the second instance
of Windows; exit this instance of Windows and run your
application from the original.
In the MS-DOS Shell, the Enable Task Swapper option should be displayed
(that is, it should not have a check mark beside Enable Task Swapper on the
Option menu). This option is a toggled selection: choosing Enable Task
Swapper the first time enables it; choosing it again disables it.
The following error may be displayed if you try to run Windows in 386
enhanced mode from within the MS-DOS Shell (regardless of the Enable Task
Swapper option status):
Insufficient memory to run application; close one or more
applications to increase available memory and try again.
At this point, exit Windows, exit MS-DOS Shell, and start Windows from the
MS-DOS command prompt.
Second Instance of Windows Started from an Application
Starting a Windows application such as Microsoft Excel, Microsoft Project,
or Microsoft PowerPoint from an MS-DOS batch file inside Windows starts
another instance of Windows.
Large Windows applications such as these start an instance of Windows
when the application's executable filename is invoked. Smaller Windows
applications, such as Notepad, do not start another instance of Windows.
For example, if you type
EXCEL at an MS-DOS
command prompt, Microsoft Excel starts as does a new instance of Windows.
If you type
NOTEPAD at an MS-DOS command
prompt, Notepad does not start unless you type
WIN before the command
(that is,
WIN NOTEPAD).