How to prevent Wix from removing registry entries on uninstall?
Set the Permanent="yes" attribute on the parent component.
http://wix.sourceforge.net/manual-wix3/wix_xsd_component.htm
PermanentYesNoTypeIf this attribute is set to 'yes', the installer does not remove thecomponent during an uninstall. The installer registers an extra systemclient for the component in the Windows Installer registry settings(which basically just means that at least one product is alwaysreferencing this component). Note that this option differs from thebehavior of not setting a guid because although the component ispermanent, it is still patchable (because Windows Installer stilltracks it), it's just not uninstallable.