Hi, once pro tools is open, at the top menu under setup / playback engine
set the number or processors to one less than pro tools allows.
I would recommend you get your ram up to 8GB ($50) or 16GB ($50-$75). Its super cheap now. You probably have 4GB.
here are some other helpful hints
http://blog.mixonline.com/mixblog/20...w-to-fix-them/
THe sampletron content should be ok on the SSD, but you can experiment and see if it gives better performance by putting the content on the external drive. I am also assuming your external drive is a firewire drive.
Chris