Checkink HKCU hive key first make sense. You can have more than one user on PC and each user can pick their own default email client.

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>Thanks. That's correct except on Vista (on the machine I am using) there is another key in
>HKEY_CURRENT_USER\SOFTWARE\Clients\Mail
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>It would appear that's that one Vista is updating consistently. Changing default email client didn't change the value in HKEY_LOCAL_MACHINE entry.
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>I take I hove to look in current_user first. Any comments will be much appreciated.
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