When you try to add lots of .pst files to your e-mail profile in Outlook 2003, some of the .pst files may not be added (907651)

Important This article contains information about how to modify the registry. Make sure to back up the registry before you modify it. Make sure that you know how to restore the registry if a problem occurs. For more information about how to back up, restore, and modify the registry, click the following article number to view the article in the Microsoft Knowledge Base:

256986 Description of the Microsoft Windows registry

SYMPTOMS

When you try to add lots of Personal Folders files (.pst) to your e-mail profile in Microsoft Office Outlook 2003, some of the .pst files may not be added. Additionally, you receive the following error message when you try to add these .pst files to your e-mail profile programmatically:

Outlook failed to add the personal store to the session.

Alternatively, you receive the following error message when you try to add these .pst files to your e-mail profile by using the Create or Open Outlook Data File dialog box in Outlook 2003:

Out of memory or system resources. Close some windows or programs and try again.

CAUSE

This problem occurs because Outlook 2003 allocates more memory for caching .pst files than earlier versions of Microsoft Outlook. After you enable this hotfix, Outlook 2003 allocates the same amount of memory as earlier versions of Outlook for caching .pst files.

RESOLUTION

How to obtain the hotfix

This issue is fixed in the Outlook 2003 post-Service Pack 2 Hotfix Package that is dated December 6, 2005. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

899340 Description of the Outlook 2003 post-Service Pack 2 hotfix package: December 6, 2005

How to enable the hotfix

Warning Serious problems might occur if you modify the registry incorrectly by using Registry Editor or by using another method. These problems might require that you reinstall your operating system. Microsoft cannot guarantee that these problems can be solved. Modify the registry at your own risk.

Quit Outlook 2003.
Click Start, click Run, type regedit in the Open box, and then click OK.
Locate and then click the following registry subkey:
HKEY_CURRENT_USER\Software\Microsoft\Office\11.0\Outlook\PST
On the Edit menu, point to New, and then click DWORD Value.
Type UseLegacyCacheSize, and then press ENTER.
Right-click UseLegacyCacheSize, and then click Modify.
In the Value data box, type 1, and then click OK.
On the File menu, click Exit to quit Registry Editor.