Devicehigh

Applies To: Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2

Devicehigh

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.

Syntax

devicehigh=[Drive**:**][Path] FileName [DD-Parameters]

devicehigh size= HexSize [Drive**:**][Path] FileName [DD-Parameters]

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.

Remarks

• 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).

Examples

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:

device=c:\windows\system32\himem.sys

dos=umb

devicehigh=mydriv.sys

Formatting legend

See Also

Concepts

Loadhigh
Device
Dos
Mem
Command-line reference A-Z
Command shell overview