When attempting to install the Out'n About! for Outlook Client, registering the DLL fails.
This problem can be reproduced by running regsvr32.exe OutAboutOutlook.dll
Regsvr32.exe fails with a message box displaying:
DllRegisterServer in OutAboutOutlook.dll failed.
Return code was: 0x80070005
The error value '0x80070005' means 'Access Denied'.
This means that an attempt has been made to update part of the registry that you do not have permissions to update. There are many parts of the registry that can be read but not updated (except by 'system' or the local administrator).
Check that you have local administration rights.
If you are a local administrator (i.e. a member of the 'Administrators' group on the workstation) then most likely someone or some application has modified the permissions on one or more registry keys and that this is preventing access.
To identify which registry key is causing the problem use Regmon to capture all registry access when regsvr32 is run. If an 'OpenKey' request fails with 'Access Denied' (which is listed by Regmon as 'ACCDENIED') then run regedt32 and check the permissions on that registry key. If necessary change the permissions on the key to grant local Administrators 'Full Control'; then try registering the OutAboutOutlook.dll again.
You may have to repeat this process if more than one registry key is locked.