Windows XP A to Z - http://www.softwaretipsandtricks.com/windowsxp
Changing mailto defaults
http://www.softwaretipsandtricks.com/windowsxp/articles/333/1/Changing-mailto-defaults
Super Admin
 
By Super Admin
Published on 02/24/2005
 
Clicking on a mailto: link in IE launches Outlook even if the default mail client is changed to something else.

Changing mailto defaults

This forces mailto: links to open in Netscape 6, though varying the command line should allow you to use other clients.

1. Run regedit
2. Go to: HKEY_CLASSES_ROOT\mailto\shell\open\command
3. Change the default value to: C:\PROGRA~1\NETSCAPE\NETSCA~1\NETSCP6.EXE -mail "%1"
(for Netscape 6. Other clients will have their own command lines)

Now sit back and avoid the viruses!