Windows NT Global Groups Are Limited to 20 Character Names

This article was previously published under Q131417
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Custom applications that creates Windows NT Global Groups with names longerthan 20 characters appear to work correctly. However, when you attempt toview, modify, or delete these global groups with User Manager for Domains,the following message appears:
The following error occurred accessing the properties of the group <Large Group Name>:

The filename, directory name, or volume label syntax is incorrect.

The group properties cannot be edited or viewed at this time.
Windows NT 3.1, 3.5, 3.51, and 4.0 do not support Windows NT global groups withnames longer than 20 characters. This limit is imposed to allow forinteroperability with OS/2 LAN Manager, DOS LAN Manager, IBM LAN Server,and Windows for Workgroups.

Limit the length of global group names to 20 characters (as defined by theconstant LM20_GNLEN in LMCONS.H). Local groups are not limited to 20characters so they may be used where large group names are required.

The following functions should use global group names that are no greaterthan LM20_GNLEN bytes in length.
   NetGroupAdd   NetGroupAddUser   NetGroupEnum   NetGroupGetInfo   NetGroupSetInfo   NetGroupDel   NetGroupDelUser   NetGroupGetUsers   NetGroupSetUsers   NetUserSetGroups				

There is no function to rename a global group name.

Other APIs that manipulate global groups should not be used withglobal groups that have names exceeding 20 characters as the results areunpredictable.


Article ID: 131417 - Last Review: 02/28/2014 07:56:42 - Revision: 3.0

  • Microsoft Windows NT Advanced Server 3.1
  • Microsoft Windows NT Workstation 3.1
  • Microsoft Windows NT Advanced Server 3.1
  • Microsoft Windows NT Workstation 3.5
  • Microsoft Windows NT Workstation 3.51
  • Microsoft Windows NT Workstation 4.0 Developer Edition
  • Microsoft Windows NT Server 3.5
  • Microsoft Windows NT Server 3.51
  • Microsoft Windows NT Server 4.0 Standard Edition
  • Microsoft LAN Manager 2.2 Standard Edition
  • kbnosurvey kbarchive kbapi kbnetwork kbui KB131417