I've upgraded my Outlook from 2000 to 2007. After install I get the
message..... An extension failed to initialize. Cannot open file:
extend.dat. The file may not exist, you may not have permission to open it or
it may be open in another program. Right click the folder that contains the
file and then click [properties to check your permissoions for the folder.

I c annot find the file on my computer.

I tried un-installing and re-installing with the same error.