PRB: KRNL386: Unable to Enter Protected Mode
Article ID: 105207
Article Last Modified on 11/6/1999
APPLIES TO
- Microsoft Windows Software Development Kit 3.1
This article was previously published under Q105207
SYMPTOMS
Windows 3.1 fails to boot and returns to MS-DOS with a "KRNL386: Unable to
enter Protected Mode" error message. This usually occurs after switching to
the debug version of Windows.
CAUSE
Windows 3.1 was started with old files left over from an upgraded
installation of Windows 3.0 with the Windows 3.0 Software Development Kit
(SDK).
RESOLUTION
Replace the old files with the correct versions. The files of importance
are KRNL386.*, KRNL286.*, GDI.*, and USER.*. The old files are from 1990
and the new files are from 1992. Sort by date, and replace these old files
with the correct versions.
MORE INFORMATION
It's generally a good idea to start with a fresh installation of Windows in
a clean directory when this problem occurs. This ensures that other
obsolete files are cleared from the upgraded 3.0 installation.
Additional query words: 3.10 no32bit
Keywords: kb16bitonly KB105207