Error Opening Outlook and Control Panel's Mail Applet

Last reviewed on January 6, 2014

We're seeing reports that Outlook won't open, returning a (basically useless!) error message that Outlook won't open. Attempting to open the Mail applet in the Control panel results in an error message that Outlook is out of memory or system resources.

"You need more memory or system resources. Please close some Windows and try again."

To get Outlook back into working mode, open the registry editor and delete or rename the windows messaging subsystem key. We don't know why the key is corrupt, but this seems to fix the problem and doesn't take as much effort as completely removing Office and reinstalling.

Renaming this key means you will lose your profile and will need to recreate it. There really is no way to avoid this. Sorry.

Outlook 2010 and older:

HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Windows Messaging Subsystem

Outlook 2013:


Edit the Registry

  1. Press Windows key + R to open the Run command.
  2. The renamed registry keyType regedit in the Open field and click OK.
  3. Locate the key then right click on it and choose Rename.
  4. Type OLD at the end of the name.
  5. Try opening the Mail applet to create a new profile.

If Outlook works, you can delete the renamed key.

<Use the registry editor to rename the key

In Outlook 2013, the key is at HKEY_CURRENT_USER\Software\Microsoft\Office\15.0\Outlook\Profiles
Outlook 2013's profile key

Written by

Diane Poremsky
A Microsoft Outlook Most Valuable Professional (MVP) since 1999, Diane is the author of several books, including Outlook 2013 Absolute Beginners Book. She also created video training CDs and online training classes for Microsoft Outlook. You can find her helping people online in Outlook Forums as well as in the Microsoft Answers and TechNet forums.

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