How to Speed up Outlook 2007 on XP and Vista by Removing Outlook DAT Files

Outlook uses .DAT files to keep operating smoothly. If your outlook is moving slow or doesn’t load or isn’t responding, then try restoring the following .DAT files.  This can be done by doing the following:

1. Closing Outlook
2. Find the .DAT files listed below
3. Rename or delete them (preferably rename so that you can restore if the need arises)
4. Launch outlook (this will create new .dat files)

OUTCMD.DAT - This file is usually the problem, and can cause Outlook not opening/loading/ moving slow and also missing or corrupt toolbar and menu.

This is where Outlook stores all the changes that are made to the toolbar. The toolbar is where Adware, Spyware and Virus applications normally hit. This can also become corrupt as a result of installing 3^rd party toolbars and/or add-ons. OUTCMD.DAT becomes corrupt and the result is that Outlook doesn’t load or loads slowly.

OUTCMD.DAT can be located at the following location

XP – “C:\Documents and Settings\username\Application Data\Microsoft\Outlook”
Vista/Windows 7 – “C:\Users\username\AppData\Roaming\Microsoft\Outlook”

EXTEND.DAT – internal cache file used by Outlook to store paths to all DLL files used for Outlook extensions

EXTEND.DAT can be found at the following location

XP – “C:\Documents and Settings\username\Application Data\Microsoft\Outlook”
Vista/Windows 7 – “C:\Users\username\AppData\Local\Microsoft\Outlook”

FRMCACHE.DAT – An index of the individual forms that have been cached on the computer

FRMCACHE.DAT  can be found at the following location

XP – “C:\Documents and Settings\username\Application Data\Microsoft\Outlook”
Vista\Windows 7 – “C:\Users\username\AppData\Local\Microsoft\FORMS”

VIEWS.DAT – This file will only exist if you have created a custom view of your folder

VIEWS.DAT can be found at the following location

XP – “C:\Documents and Settings\username\Application Data\Microsoft\Outlook”
Vista/Windows 7 – “C:\Users\username\AppData\Local\Microsoft\Outlook”