Poser8 is a 32 bit application. Adding RAM will not help you in the GUI.
Rendering in a seperate process could help speed up render times if you have a heavy scene. Set it in Posers General preferences.

First do a system cleanup.
I Use all of them but try :

• CCleaner, a free app,  use the Ccleaner and then the registry cleaner
• Glary Utilities, a free app, one click solution
• Winutilities, a free app, one click solution

I would advice this last one to start with:

• Advanced system care free, version 4.2 is the latest,  from iobit, a free app, one click solution, Select=> Deep clean, select all options exept defrag, and let it Scan and repair. (Small arrow in the Scan button)

Download and install; Smartdefrag 2.2, also free, and from iobit.
Install and let it do its thing in the background.

And please, do not install the toolbars.
It seems everone wants us to have more and more toolbars, oh boy.

Also, and please say no.
You are not running anything from Norton?? Are you???

Poser 1, 2, 3, 4, 5, 7, P8 and PPro2010, P9 and PP2012, P10 and PP2014 Game Dev
"Do not drive faster then your angel can fly"!