Loads device drivers into the upper memory area. This frees more bytes of conventional memory for other programs. Use the systemroot\System32\Config.nt file, or the equivalent startup file specified in a program's PIF, to load device drivers for the MS-DOS subsystem.


devicehigh=[Drive:][Path] FileName [dd-parameters]

devicehigh size= hexsize [Drive:][Path] FileName [dd-parameters]


[ Drive : ][ Path ] FileName : Specifies the location and name of the device driver you want to load into the upper memory area. Filename is required.

dd-parameters : Specifies any command-line information required by the device driver.

hexsize : Required. Specifies the minimum amount of memory (that is, the number of bytes, in hexadecimal format) that must be available before devicehigh attempts to load a device driver into the upper memory area. You must use both size and hexsize, as shown in the second syntax line.

/? : Displays help at the command prompt.


  • Using dos=umb

    To use devicehigh, you must also include dos=umb in your Config.nt or equivalent startup file. If you do not specify dos=umb, all device drivers are loaded into conventional memory, as if you had used the device command. For more information about the dos=umb , see Related Topics.

  • Installing Himem.sys

    Before you can load a device driver into the upper memory area, you must use device to install the Himem.sys device driver. Device must appear before any devicehigh command in your Config.nt or equivalent startup file.

  • Specifying a size limit

    If the device driver you specify attempts to allocate more buffer space than is available in a block of the upper memory area, your system might lock up. Use hexsize to avoid this problem. In hexsize, indicate the amount of memory the device driver needs in hexadecimal format. To find this value for a particular device driver, load the driver into conventional memory and run mem /debug.

  • Loading into conventional memory

    If there is not enough upper memory area available to load the device driver you specified in devicehigh, the MS-DOS subsystem loads it into conventional memory (that is, as if you used device).


To load a device driver named Mydriv.sys into the upper memory area, type the following commands in your Config.nt or equivalent startup file:


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Information that the user must supply


Elements that the user must type exactly as shown

Ellipsis (...)

Parameter that can be repeated several times in a command line

Between brackets ([])

Optional items

Between braces ({}); choices separated by pipe (|). Example: {even|odd}

Set of choices from which the user must choose only one

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Code or program output





Command-line reference A-Z