For information about differences between Microsoft Outlook Express and
Microsoft Outlook e-mail clients, reference the article number below to
view the article in the Microsoft Knowledge Base:
 
 Q257824 OL2000: Differences Between Outlook and Outlook Express
 
IMPORTANT: This article contains information about editing the registry.
Before you edit the registry, make sure you understand how to restore it
if a problem occurs. For information about how to do this, view the
"Restoring the Registry" Help topic in Regedit.exe or the "Restoring a
Registry Key" Help topic in Regedt32.exe.
 
SYMPTOMS
========
 
When you use Outlook Express, you may receive the following error message:
 
Msimn.exe has generated errors and will be closed by Windows. You will need
to restart the program. An error log is being created.
 
CAUSE
=====
 
This error may be a result of a damaged Identities key in the registry.
 
RESOLUTION
==========
 
Before you resolve this problem, it is recommended that you back up your
messages and addresses. For additional information about backing up messages
and addresses, click the article numbers below to view the articles in the
Microsoft Knowledge Base:
 
  Q230208 How to Back Up E-mail Messages in Outlook Express 5

  Q175017 How to Import and Export Address Books in Outlook Express

Additionally, it is recommended that you back up your Internet Mail account
information. The account configuration in Outlook Express provides a method
for backing up these settings.

To export your mail account information:

1. On the Tools menu, click Accounts.

2. Click the account that you want to export, and then click Export.

3. In the Export Internet Account box, type a descriptive file name, and
   then click Save.

NOTE: This procedure needs to be performed for each account.

An option to import settings is available in the Internet Accounts of
Control Panel. This option lets you restore your account information.

Regenerating the Identities Registry Key
----------------------------------------

WARNING: Using Registry Editor incorrectly can cause serious problems that
may require you to reinstall your operating system. Microsoft cannot
guarantee that problems resulting from the incorrect use of Registry Editor
can be solved. Use Registry Editor at your own risk.

For information about how to edit the registry, view the "Changing Keys and
Values" Help topic in Registry Editor (Regedit.exe) or the "Add and Delete
Information in the Registry" and "Edit Registry Data" Help topics in
Regedt32.exe. Note that you should back up the registry before you edit it.
If you are running Windows NT or Windows 2000, you should also update your
Emergency Repair Disk (ERD).

To regenerate the Identities registry key:

1. Click the Start button, click Run, and then type "regedit" (without the
   quotation marks). Click OK.

2. Browse through the registry to the following registry key:

   HKEY_CURRENT_USER/Identities

3. On the Registry menu, click Export Registry File.

4. In the Save In box, click Desktop.

5. In the File Name box, type "Identities" (without the quotation marks),
   and then click Save.

6. In Registry Editor, right-click the Identities key, and then click Delete.

7. Quit Registry Editor, and then start Outlook Express to test functionality.

You can now restore your mail, addresses, and account settings.