When the user installs Vitals, (Example was when the user installed Vitals 3.6.3), and then it asks for default email client(Microsoft Office Outlook) when installing WMDC.
This issue ended up being by the fact that the settings int he HC100 hand-held somehow changed.
The resolution is to either do a factory rest on the handheld or to follow the steps below to change the setting back to what they should be:
3. , then click on ActiveSync
4. Then click Menu and then Connections, there verify that Synchronize all PCs using this connection: check box is checked.
If you follow these steps it should resolve your issue.