Windows Environmental Variables

Source: Microsoft

Variable Type Description
%ALLUSERSPROFILE% Local Returns the location of the All Users Profile.
%APPDATA% Local Returns the location where applications store data by default.
%CD% Local Returns the current directory string.
%CMDCMDLINE% Local Returns the exact command line used to start the current Cmd.exe.
%CMDEXTVERSION% System Returns the version number of the current Command Processor Extensions.
%COMPUTERNAME% System Returns the name of the computer.
%COMSPEC% System Returns the exact path to the command shell executable.
%DATE% System Returns the current date. Uses the same format as the date /t command. Generated by Cmd.exe.
%ERRORLEVEL% System Returns the error code of the most recently used command. A non zero value usually indicates an error.
%HOMEDRIVE% System Returns which local workstation drive letter is connected to the user’s home directory. Set based on the value of the home directory. The user’s home directory is specified in Local Users and Groups.
%HOMEPATH% System Returns the full path of the user’s home directory. Set based on the value of the home directory. The user’s home directory is specified in Local Users and Groups.
%HOMESHARE% System Returns the network path to the user’s shared home directory. Set based on the value of the home directory. The user’s home directory is specified in Local Users and Groups.
%LOGONSEVER% Local Returns the name of the domain controller that validated the current logon session.
%NUMBER_OF_PROCESSORS% System Specifies the number of processors installed on the computer.
%OS% System Returns the operating system name. Windows 2000 displays the operating system as Windows_NT.
%PATH% System Specifies the search path for executable files.
%PATHEXT% System Returns a list of the file extensions that the operating system considers to be executable.
%PROCESSOR_ARCHITECTURE% System Returns the chip architecture of the processor. Values: x86, IA64.
%PROCESSOR_IDENTFIER% System Returns a description of the processor.
%PROCESSOR_LEVEL% System Returns the model number of the processor installed on the computer.
%PROCESSOR_REVISION% System Returns the revision number of the processor.
%PROMPT% Local Returns the command prompt settings for the current interpreter. Generated by Cmd.exe.
%RANDOM% System Returns a random decimal number between 0 and 32767. Generated by Cmd.exe.
%SYSTEMDRIVE% System Returns the drive containing the Windows XP root directory (that is, the system root).
%SYSTEMROOT% System Returns the location of the Windows XP root directory.
%TEMP% and %TMP% System and User Returns the default temporary directories that are used by applications available to users who are currently logged on. Some applications require TEMP and others require TMP.
%TIME% System Returns the current time. Uses the same format as the time /t command. Generated by Cmd.exe.
%USERDOMAIN% Local Returns the name of the domain that contains the user’s account.
%USERNAME% Local Returns the name of the user who is currently logged on.
%USERPROFILE% Local Returns the location of the profile for the current user.
%WINDIR% System Returns the location of the operating system directory.

WMI repair

For Windows XP Service Pack 2

Click Start, Run and type the following command:

rundll32 wbemupgd, UpgradeRepository

For Windows Server 2003

Use the following command to detect and repair a corrupted WMI Repository:

rundll32 wbemupgd, RepairWMISetup

Re-registering the WMI components (Ref WMI FAQ)

The .DLL and .EXE files used by WMI are located in %windir%system32wbem. You might need to re-register all the .DLL and .EXE files in this directory. If you are running a 64-bit system you might also need to check for .DLLs and .EXE files in %windir%sysWOW64wbem.
To re-register the WMI components, run the following commands at the command prompt:

  • cd /d %windir%system32wbem
  • for %i in (*.dll) do RegSvr32 -s %i
  • for %i in (*.exe) do %i /RegServer