No, you don't need to uninstall your Vue 4 copy, only Vue Pro. Going into the registries is a very tricky thing if you are not used to it. If you do something wrong, your computer may become very, very ill!! But if you follow EXACTLY this, you will have no problem: To go into the registry, click START/EXECUTE and type "regedit" (without the quotes). Click OK. This opens the registry. First open the folder called HKEY_CURRENT_USER There you find the folder "Software". Open it. In there you will find the folder "e-onsoftware", open it and delete the entire folder called "Vue 4 Professional". Do not delete the folder "Vue d'Esprit" if you have one in there. Close the folder called HKEY_CURRENT_USER ___________________ Now open the folder called HKEY_LOCAL_MACHINE In there, open the folder SOFTWARE In there open the folder e-onsoftware In there delete ONLY the entire folder "Vue Pro" Close the folder HKEY_LOCAL_MACHINE Close the Registry. _______________ Delete VuePro.reg from the Windows folder. Make sure the old folders of Vue 4 Pro are completely deleted too from your HD. Just save your objects, plants to a save place before you do so. You can put them back when Vue 4 Pro is properly installed. Restart your computer. re-install Vue 4 Pro where you want. I cannot be helpful for your Poser Pro pack, because I don't have it. See what happens, when you have installed Vue 4 pro again. Guitta