Nuked my keyfiles

[Lee Fisher]

> There's not much consensus on this among Windows software developers.

MSDN: Windows Installer Best Practices
http://msdn.microsoft.com/en-us/library/bb204770(VS.85).aspx#uninstall_clean

----snip----
Uninstallation leaves the user's computer in a clean state.

Application removal is as important as installation. When a Windows 
Installer package is uninstalled it should leave no useless parts of 
itself behind on the user's computer.

     * If a file that should have been removed from the user's computer 
remains installed after running an uninstall, the installer may not be 
removing the component containing the file for one or more of the 
reasons described in Removing Stranded Files.

     * If an application must be registered, author the package to 
remove registry information when the application is uninstalled. For 
information see Adding or Removing Registry Keys on the Installation or 
Removal of Components. If an application is not registered, the 
application is not listed in the Add or Remove Programs feature in 
Control Panel and cannot be managed by using the Windows Installer.

     * To hide an application from the Add or Remove Programs feature in 
Control Panel and still be able to use the Windows Installer to manage 
the application, follow the guidelines described in Adding and Removing 
an Application and Leaving No Trace in the Registry.

     * Custom actions should be conditioned to run or not as needed upon 
uninstallation. Different custom actions may need to run on install and 
uninstall.

     * User-specific customization information can be stored in a text 
file on the computer. This has the advantage that the file can be 
removed when the application is uninstalled, even if the user of this 
customization is not currently logged on.
----snip----