Q. I work for a very large company and I don't have enough space on my C drive for the Offline Address Book that Outlook stores. Can I move it?

A. Wow, that's a big company . By default, the Offline Address Book (OAB) resides in %USERPROFILE%\AppData\Local\Microsoft\Outlook\Offline Address Books\<profile>. You'll see six different OAB files that contain the address book's content.

If you need to change this location, you can update a registry value, as outlined here.

1. Close Outlook.
2. Start the registry editor (regedit.exe).
3. Move to HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Windows Messaging Subsystem\Profiles\<profile name>\13dbb0c8aa05101a9bb000aa002fc45a.
4. From the Edit menu, select New, DWORD value.
5. Enter a name of 001e660e and press Enter.
6. Double-click the new value and set it to the new path for the OAB, then click OK.

Close the registry editor and restart Outlook.