voici la solution ( en direct du support microsoft )
1- Exit Outlook 2002, if running.
2- Click the Windows Start button, and then click Run.
3- In the Open box, type regedit, and then click OK.
4- Check to see if the following key exists. If it does, skip to step 5.
HKEY_CURRENT_USER\Software\Microsoft\Office\10.0\Outlook\Security
If the key path does not exist, create the key path. To create the key path, navigate to and select the key:
HKEY_CURRENT_USER\Software\Microsoft
a- Click the Edit menu, click New, and then click Key.
b- Type Office and press ENTER.
c- Click the Edit menu, click New, and then click Key.
d- Type 10.0 and press ENTER.
e- Click the Edit menu, click New, and then click Key.
f- Type Outlook and press ENTER.
g- Click the Edit menu, click New, and then click Key.
h- Type Security and press ENTER.
5- Click the Edit menu, click New, and then click String Value.
6- Type the following name for the new value:
Level1Remove
7- Press ENTER.
8- Right-click the new string value name, and then click Modify.
9- Type the extension of the file type that you would like to access with Outlook 2002 as follows:
exe
To specify multiple file types, use the following format:
.exe;.com
10- When finished, click OK.
11- Exit the Registry Editor program.
12- Restart the computer.
When you start Outlook 2002, the file types specified in the Windows Registry are accessible.
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