VB provides an easy way to access the Registry with the built-in GetSetting and SaveSetting functions. These functions read and write information to the HKEY_CURRENT_USERSoftwareVB and VBA Program area of the Registry. VB6 makes it easy to create DLLs that can run in Microsoft Transaction Server (MTS) on an NT Server. A problem occurs, however, when you create an ActiveX DLL that uses GetSetting or SaveSetting in a DLL running on an NT Server that has no current user.
In MTS, you can set up a user under the Identity tab of the Property settings for an MTS package. Selecting a user under the Identity tab is supposed to allow your DLL to run even if there is no currently logged-in user on the server. However, even with that user identified in MTS, your DLL still fails to run if it uses GetSetting or SaveSetting. Apparently, the VB DLL is unable to locate the HKEY_CURRENT_USER hive of the Registry if there is no current user. No error is returned to your calling app, while a variety of errors can be generated on the server in the event log, related to errors in MTS. The only workarounds seem to be either not using Registry settings (use hard-coded values or read a text file instead) or avoiding VB’s native Registry functions and calling the API Registry functions directly to store and retrieve information in some other part of the Registry, such as HKEY_LOCAL_MACHINE.
Editor’s Note: A third option, for the masochists out there, might be to load a given user’s hive programmatically. See the Microsoft Knowledge Base article Q168877 for details.