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Article ID: 135524 - Last Review: November 2, 2013 - Revision: 4.0

This article was previously published under Q135524
This article has been archived. It is offered "as is" and will no longer be updated.


If you use the Diskeeper 1.0 from Diskeeper Corporation uninstall feature after you upgrade Windows NT 3.5 to 3.51 and restart your computer, you receive an entry point error in NTDLL.DLL and Windows NT hangs and becomes unbootable. 

NOTE: Diskeeper for Windows NT is a disk defragmentation program for Windows NT 3.5.


Diskeeper version 1.0 is not designed to run under Windows NT 3.51.

When you install Diskeeper on Windows NT 3.5, Diskeeper replaces the following Windows NT system files with its own versions of these files: NTDLL.DLL, NTOSKRNL.EXE, FASTFAT.SYS, and NTFS.SYS. If you use the Diskeeper uninstall feature after you upgrade to Windows NT 3.51, Diskeeper replaces the Windows NT 3.51 versions of these files with the Windows NT 3.5 versions. These do not work with Windows NT 3.51.


Run the emergency repair disk (ERD) to recover your Windows NT 3.51 boot and system files. Do not run Diskeeper version 1.0 under Windows NT 3.51.
Diskeeper 1.01, which works with Windows NT 3.51, is no longer available from Diskeeper Corporation.

More information

The latest version of Diskeeper is available at Diskeeper Corporation’s website: (

For additional information, contact Diskeeper Corporation at:

Diskeeper Corporation
7590 N. Glenoaks Blvd
Burbank, CA 91504

Technical Support: (818)771-1600
Fax: (818)252-5514

Applies to
  • Microsoft Windows NT Workstation 3.51
  • Microsoft Windows NT Server 3.51
kbnosurvey kbarchive kb3rdparty KB135524
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