Comments on: Outlook 2007 extend.dat error

By: wake5

wake5 — Sat, 12 May 2012 03:17:00 +0000

Just in case this helps anybody below is where I found the “extend.dat” file in Win 7 64 bit… I guess Microsoft likes to move stuff around with every new operating system aimlessly and for no good reason. BTW the search in Windows did find this file, I’m sure its due to its hidden nature, Microsoft tries to hide stuff from us dummy operators so we don’t hurt ourselves, or is it so we have to contact them and pay them for help when something goes wrong??

The “Wake” in the path below was my user name on the computers.

C:UsersWakeAppDataLocalMicrosoftOutlook

By: shuufu

shuufu — Fri, 26 Aug 2011 18:57:55 +0000

renaming the extend.dat file works. Outlook seems to have created another extend.dat file. and no more warning window comes up again. Thank you.

By: rakei

rakei — Wed, 29 Dec 2010 22:24:35 +0000

It has to do with some Anti-virus program, usually the error are more likely related if you are using Avast, or any malware, anti-virus program. Uninstall the program, restart you P.C and see if that fixes it.

Otherwise located the extend.dat file manually and delete. restart p.c and open microsoft outlook again, This will help microsoft Outlook to reset itself. it should work. Heres the location……

Winxp: ‘C:Documents and SettingsLocal SettingsApplication DataMicrosoftOutlookextend.dat

win7: cuseradminappdatalocalmicrosoftoutlookextend.dat

By: carlosdl

carlosdl — Thu, 02 Dec 2010 17:28:39 +0000

Now, maybe creating a new profile might help. If that doesn’t help you might want to backup your data store and reinstall Outlook.