Error 8002801d Library not registered when viewing Calendars or Saving AddressBook entries When attempting to view the Calendars, add a new AddressBook entry or make any changes to your account in Express, the following error is returned: error '8002801d' Library not registered. ?, line 0 This is due to a problem with the VB Script Engine. You can try to register the vbscript.dll file 1. Access the Command Prompt. 2. Navigate to C:\Windows\System32 (Windows default). 3. Type 'regsvr32 vbscript.dll'. 4. Restart IIS 5. Log back into Express and attempt to view your Calendar. If this does not remedy the problem, then you should try to reinstall the Microsoft VB Script Engine available from www.microsoft.com for your Operating System.