Cannot use Word to Compose E-Mail

[KGS]

For some reason, a couple of weeks ago, Outlook started using Rich Text for the message format for composing e-mail. I went into Tools > Options > Mail Format, and the entire Message Format area is greyed out. I have been able to change a couple of things in the Message Format area using the Registry, but I have not been able to change the "Compose in this message format" box from Rich Text to Used Word as E-Mail Editor. I'm also afraid that when I restart the computer my registry settings will reset to my current settings (it has happened before). I don't know if it is my network or what, but something keeps resetting my registry when I make small changes like this.