Issue:
When I try to add a new user to the local machine PowerUsers (or any group for that matter) I get the following error: An error occurred attempting to create the Object Picker. An error with no description has occurred.

Solution:
This error can occur when either of the following registry keys is missing or corrupted:

HKEY_CLASSES_ROOT\CLSID\{080d0d78-f421-11d0-a36e-00c04fb950dc}

HKEY_CLASSES_ROOT\LDAP

{228D9A81-C302-11cf-9AA4-00AA004A5691}

NOTE: If your registry keys contain values rather than being blank or missing, you should first back up the keys by using the Export Registry Key feature in Regedit.exe. You should then examine the entries for differences and merge them if you need to.

If the HKEY_CLASSES_ROOT\CLSID\{080d0d78-f421-11d0-a36e-00c04fb950dc} key is missing or damaged, add the following lines to a text file, rename it with a .reg extension, and then import it to your registry.

On a Windows 2000-based domain controller use the following text:

Windows Registry Editor Version 5.00

[HKEY_CLASSES_ROOT\CLSID\{080d0d78-f421-11d0-a36e-00c04fb950dc}] @="ADs LDAP Pathname Descriptor Object"

[HKEY_CLASSES_ROOT\CLSID\{080d0d78-f421-11d0-a36e-00c04fb950dc}\InprocServer32]@="activeds.dll"
"ThreadingModel"="Both"

[HKEY_CLASSES_ROOT\CLSID\{080d0d78-f421-11d0-a36e-00c04fb950dc}\ProgID] @="Pathname"

[HKEY_CLASSES_ROOT\CLSID\{080d0d78-f421-11d0-a36e-00c04fb950dc}\TypeLib] @="{97d25db0-0363-11cf-abc4-02608c9e7553}"

[HKEY_CLASSES_ROOT\CLSID\{080d0d78-f421-11d0-a36e-00c04fb950dc}\Version] @="0.0"

On a Windows 2000-based domain member computer use the following text:

Windows Registry Editor Version 5.00

[HKEY_CLASSES_ROOT\CLSID\{080d0d78-f421-11d0-a36e-00c04fb950dc}] @="ADs Pathname Object"

[HKEY_CLASSES_ROOT\CLSID\{080d0d78-f421-11d0-a36e-00c04fb950dc}\InprocServer32]@="activeds.dll"
"ThreadingModel"="Both"

[HKEY_CLASSES_ROOT\CLSID\{080d0d78-f421-11d0-a36e-00c04fb950dc}\ProgID] @="Pathname"

[HKEY_CLASSES_ROOT\CLSID\{080d0d78-f421-11d0-a36e-00c04fb950dc}\TypeLib] @="{97d25db0-0363-11cf-abc4-02608c9e7553}"

[HKEY_CLASSES_ROOT\CLSID\{080d0d78-f421-11d0-a36e-00c04fb950dc}\Version] @="0.0"

If the HKEY_CLASSES_ROOT\LDAP key is missing, or damaged, use the following text:

Windows Registry Editor Version 5.00

[HKEY_CLASSES_ROOT\LDAP]
@="URL:LDAP Protocol"
"EditFlags"=hex:02,00,00,00
"URL Protocol"=""

[HKEY_CLASSES_ROOT\LDAP\Clsid]
@="{228D9A81-C302-11cf-9AA4-00AA004A5691}"

[HKEY_CLASSES_ROOT\LDAP\shell]

[HKEY_CLASSES_ROOT\LDAP\shell\open]

[HKEY_CLASSES_ROOT\LDAP\shell\open\command]
@="\"D:\\Program Files\\Outlook Express\\wab.exe\" /ldap:%1"

I have created these reg files in zip for easy download... see below.