File Manager Cannot Format Drive the System Was Started From (83972)

The information in this article applies to:
    Microsoft Windows 3.1
    Microsoft Windows 3.11
    Microsoft MS-DOS operating system 4.0
    Microsoft MS-DOS operating system 4.01
    Microsoft MS-DOS operating system 5.0

This article was previously published under Q83972


When you use File Manager (WINFILE.EXE) in the Microsoft Windows operating system version 3.1, you cannot format the drive that the system was started from. For example, if the machine was started from drive A, you cannot format a disk in drive A from File Manager. If you try to do this, Windows generates the following error message:

Cannot format the MS-DOS startup drive
NOTE: This problem occurs only with versions of MS-DOS later than 4.01.


File Manager attempts to read the boot sector from the boot drive the system was started from in order to format a disk. If File Manager tries to format the disk in the drive the system was started from, it has to assume that the drive has no boot sector on it and that it cannot to obtain one.

Microsoft has confirmed this to be a problem in Windows version 3.1 File Manager. We are researching this problem and will post new information here as it becomes available.

Modification Type: Major Last Reviewed: 11/26/2003
Keywords: KB83972