How do I backup Outlook Rules?

Wizard Rules are stored in .rwz files with the name of your profile in default Outlook directory. To open the default folder for Outlook files go to Start > Run and insert one of the below paths depending on your operating systems:

XP: %USERPROFILE%\Application Data\Microsoft\Outlook
VISTA: %USERPROFILE%\AppData\Roaming\Microsoft\Outlook 

To export the rules:

Choose Tools > Rules And Alerts and then click Options. In the Options dialog box, click Export Rules, and choose a file location.

Reverse the process to import your saved rules if you need to transfer Outlook to another machine.

Always check all the imported rules to make sure they're still active. Sometimes they're deactivated (especially move or copy to folder rules) because Outlook can't be sure that the destination folder is the same as in your original rule.