I am running ArcGIS Desktop 9.3.4000 on Windows XP. I recently installed Hec-GeoHMS 184.108.40.206 on my machine. It did not work correctly so aftre reading the forums I uninstalled all legacy components (including GeoRAS), cleaned the registry, and reinstalled. It took multiple tries but I finally got it to work with ApFramework9 220.127.116.11 and ArcHydro 18.104.22.168. Today I tried to reinstall Hec-GeoRAS and received the error "An incorrect version of ApFramework9 was found on the system. HEC-GeoRAS requires Apframework9 version 22.214.171.124. Please uninstall the existing ApFramework9 version and restart this installation." If I do this I suspect that Hec-GeoHMS will not work because of incompatibility with 126.96.36.199. It seems ridiculous that you would have to uninstall and reinstall every time you switched from GeoRAS to GeoHMS. Does anybody have any insight? Are versions of HEC-GeoRAS and HEC-GeoHMS that use the same ApFramework9?