With Adobe Customization Wizard 8 the installation of Reader 8.1.2 runs very well to d:\programme\adobe\reader8.1
If an older version was installed to c:\programme\adobe\reader than the old verison is uninstalling and the new version is installed to the same path. But in the Adobe Customization Wizard 8 i configured that the installation path should be d:\programme\adobe\reader8.1.