This is what happens when a program's configuration file becomes corrupted. There is a file called 'Poser' that is a configuration settings file. It will not go away when you uninstall. You could do a search for files by the name of Poser and find the one that is of the configuration settings type. Delete it and then start Poser.  

If this doesn't work, do a search for 'preferedState' which is a Poser scene file. Delete that as well. 

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