PS/2 Appears to Hang When Exiting Windows 3.1

 Last reviewed: December 31, 1996
Article ID: Q82763
The information in this article applies to:
  • Microsoft Windows operating system versions 3.1, 3.11

SYMPTOMS

Some IBM PS/2 models may appear to stop responding (hang) when you exit Windows version 3.1. The computer eventually restarts; however, it remains frozen for up to a minute while the mouse port is reinitialized.

This problem is most severe on PS/2 models 56 and 57. It also occurs on models 50z, 55sx, 70, 80, 90, and 95.

CAUSE

This behavior is caused by a problem in the IBM PS/2 mouse BIOS.

WORKAROUND

The problem can be corrected by adding the following line to the [386Enh] section of SYSTEM.INI: 

   InitPS2MouseAtExit=FALSE
This prevents Windows from attempting to reinitialize the PS/2-style mouse port prior to exiting to MS-DOS. This may cause problems when you run some mouse-aware, MS-DOS-based applications after exiting Windows.

PS/2 products included here are manufactured by a vendor independent of Microsoft; we make no warranty, implied or otherwise, regarding these products' performance or reliability.

KBCategory: kbhw kb3rdparty kbenv
KBSubcategory: win31
Additional reference words: 3.10 3.11 InitPS2MouseAtExit ps2 hangs init
slow Initps2mouseportatexit

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Last reviewed: December 31, 1996
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