Hello Catharina...this is Bill. What you can do and should work but I can't promise anything. When you Uninstall Poser and Vue 4, make sure you go to your Explorer manager and delete all the folder and files resifue related to Vue and Poser. If you have anything important in your "Poser Runtime" amke a copy of it (so tthat you don't have to rinastall all your model etc..again) and do the same for Vue Plants (Folder). After this, go to "regedit" thru "MSDOS" mode and look for anything that is Poser (Curiouslab) or Vue (e-on) files or sub folder under "Hkey/software" and have them deleted. Also checck your Windows "Temp" file and clear them. After this reboot and start your installation again and like Artic1 said, install Poser first, then Vue. This would ensure the installation is clean and that there are no instuctions from past installation from the Window registery. Works "Wholesale" for me all the time. If you still can't, like Mike say, there is a serialize check me check him thingy going on between CL and E-on, and in this case, you may have to get a new Serial number with CL which is a "must" registered copy...especially with PPP. Good luck. Alos make sure your PPP update is up to Service Pack 3 to avoid any problem. Good luck.