Today I had an old Windows 2000 client PC  with Outlook 2003, which was being replaced by Windows 7 and Outlook 2010. Out of courtesy (and for an easy life!) I try to make the migration as seamless as possible, which includes taking along recently typed email addresses within Outlook.

Normally this is simply a case of copying the Outlook.nk2 file which is stored within C:\Documents and Settings\Username\Application Data\Microsoft\Outlook\ accross to the new PC – however, this doesn’t work with Outlook 2010. The Outlook 2010 NK2 file is actually a DAT file and is located, on the above operating systems, at C:\Users\{username}\AppData\Local\Microsoft\Outlook\RoamCache\Stream_Autocomplete_y_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx.dat (y = file index, x = random 16-byte key in hex form).

I found the following article cleared this up, and provide a simply “FixItForMe” tool, which providing that you put the old NK2 file in the normal location C:\Users\Username\AppData\Roaming\Microsoft\Outlook – the tool will take care of the conversion for you! Easy…

http://support.microsoft.com/kb/980542

Direct Link to FitIt tool : http://go.microsoft.com/?linkid=9758283