Outlook safemode command line switch

When Outlook fails to start because it crashes or stops/freezes at the splash screen, then one can try to run it in safemode where the following is disabled:

  • Extensions/Addons
  • Preview pane
  • Toolbar customization

To start in safemode use the following command line switch:

Outlook.exe /safe

More info MS KB182112
More info MS KB197180
More info MS KB296192

Note if Outlook has a slow startup or performs slowly (but can start), then one can try to activate the builtin repair tool. It can be found under Tools and Detect & Repair. Also consider to check if having installed Outlook addins that are causing problems (Antivirus addins can also malfunction). If loading local mail archives that are broken can also cause bad performance. More Info MS KB291957

Note if the safemode option solves the problem with actually starting Outlook, then renaming the following files should enable starting Outlook without safemode (Search the computer for the files):

  • Views.dat (Stores views associated with the Integrated File Management component)

    Outlook.exe /CleanViews

  • Outcmd.dat (Stores menu style settings)
  • Extend.dat (Cache for extension registry entries - More info MS KB286408)
  • Frmcache.dat (Cache for default and custom forms - More info MS KB290806)
  • Usrclass.dat

More info MS KB195754
More info MS KB232314
More info MS KB241817
More info MS KB249767
More info MS KB305928
More info MS KB320835
More info MS KB839804

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