Why MEM /C Does Not Show UMB Information (74209)

The information in this article applies to:
    Microsoft MS-DOS operating system 5.0

This article was previously published under Q74209


If you type the command MEM /C and receive information only about the conventional portion of memory, one of two things is occurring:
    The command is being given in a virtual machine, such as the MS-DOS prompt under Windows 3.0. -or-

    There are no upper memory blocks (UMBs) available or in use.


In order for upper memory block information to be displayed, the following must be in your CONFIG.SYS file:
    UMB must be specified on the DOS=HIGH or DOS=LOW line to tell MS-DOS to make UMBs available. For example:


    EMM386 must be loaded in the CONFIG.SYS file, which will map some of the available extended memory into the upper memory area (UMA) as usable UMBs. For UMB support, either the RAM or NOEMS switch must be used. For example:

    device=c:\dos\emm386.exe noems

    Note: EMM386.EXE requires that HIMEM.SYS be loaded.
For more information on the use of upper memory blocks, see pages 313-330 and 605-609 of the version 5.0 "Microsoft MS-DOS User's Guide and Reference," or query on the following words:

requirements and UMB and support and MS-DOS 5.0

Modification Type: Major Last Reviewed: 11/22/1999
Keywords: KB74209