Then, take a look at this ARTICLE for getting your computer set up for an editing session.
Next, look over this ARTICLE for more discussion on Resources, especially regarding the Windows Virtual Memory.
As a checklist, these are the main things that also will probably need to be done:
- Download and install all OS updates, and hot-fixes, and not just the Critical Updates
- Download and install the latest video card, and audio card drivers
- Check that you have the latest version of Apple's QT Player installed - even if not editing Apple source files, like MOV, PrE relies heavily on QT Player
Those still photos are also likely slowing the machine something terrible.
Resize them to no larger than 1000x750 pixels, per the FAQs to the right of this forum, and you should see spunkier performance.
Also, it will help tremendously if you render your timeline (by pressing Enter) every time there are red lines above your clips on your timeline.
Unfortunately, all that RAM isn't going to make much a difference because Premiere Elements is a 32-bit program -- so it will use at most 3 gigs of it.