Out Of Office Missing in outlook

FIX:
1.On the Tools menu, click Options, click Other, click Advanced Options, and click Add In Manager.
2.If Exchange Extensions Commands appears in the list of add-ins, click to select it.
3.If Exchange Extensions Commands is not on the list, click Install. From the list of add-ins that appears, double-click Emsuix.ecf.
4.Click OK three times to exit out of the Options pages.
5.Exit and log off.
6.Start Outlook and check to see if the Out of Office Assistant appears in the Tools menu.
If it did not install, the you need to make following registry modification for the Out of Office Assistant extension to be available in Outlook.

1.Start Registry Editor (Regedt32.exe).
2.Locate the following key in the registry:
HKEY_LOCAL_MACHINE/SOFTWARE/MICROSOFT/EXCHANGE/CLIENT/EXTENSIONS3.On the Edit menu, click Add Value, and then add the following registry value:
Value Name: Exchange Extensions
Data Type: REG_SZ
Value: 4.0;emsuix32.dll;7;011111111111110;1111011100
4.Quit Registry Editor.
You can also export this key from another system that is working.