Err Msg: Cannot Start Windows in Standard Mode (Low Memory)

• Microsoft Windows operating system versions 3.1, 3.11

SYMPTOMS

Microsoft Windows may display the following error messages when available XMS memory is below the requirement for standard mode and a UMB provider (for example, EMM386.EXE) is loaded in the CONFIG.SYS file:

   Cannot Start Windows in Standard Mode

   Make sure you are not running other protected-mode software or
   try starting Windows in 386 Enhanced mode by typing WIN /3.

   Insufficient extended memory available to run Windows

   Quit one or more applications to increase available memory or
   restart your computer.

CAUSE

Standard mode Windows 3.1 is VCPI-compliant. VCPI is an industry protocol to allow 386-based memory managers such as EMM386 to coexist with 286- protected mode MS-DOS extenders. However, under low-memory situations where available XMS is less than the Windows 3.1 standard mode requirement, UMB providers (for example, EMM386) cause Windows to generate the above error message.

Specifically with MS-DOS or the Windows 3.1 EMM386, the error message only appears with the NOEMS switch (and DOS=UMB). When EMM386 is loaded with either the RAM switch (to also provide expanded memory) or with no switch (to only provide expanded memory), Windows 3.1 will execute in standard mode.

To avoid this (low memory) error message, Windows will need more available XMS memory. If drivers for an external disk cache and/or RAMDrive are loaded, either reduce the extended memory allocated to these drivers or remove them entirely.