You need to go to Control Panel and then your security settings then turn UAC off (which I don't really recommend for most ppl) OR reinstalling Poser and letting the libraries go to their default location (My Documents) AND making sure you allow Poser access to the network. According to the OP tho, they've probably tried all that. Also wondering if the AV might be gumming up the works somehow.

I just installed the software on my Windows 8 machine and everything went off without a hitch....but then I allow the software to install content to the Documents folder every time....I don't necessarily put my content there, I link existing libraries that I have on another drive, but I allow the software to put its own content where it wants to (I almost never install the Poser content anyway).

The OP could try installing Poser to a folder other than the Programs folder just to see if maybe that IS the problem. When I used Windows 7, I used to install some programs to an "Installs" folder that I created to get around UAC without actually turning it off ;). Some programs just weren't very nice with UAC.

Laurie