Hmmm. Microsoft Speech doesn't use that much RAM. It uses far less than
Dragon Naturally Speaking. 512MB should be OK assuming there are not a lot
of other applications open at the same time. Is it just Word and Speech
running when you see the problem?
Open task manager and have a look at how much memory is being used total.
Or if you have XP professional, add the Page Faults column. Programs which
do this a lot slow down your computer a lot. My own guess is that you have
some application which is doing this. Find the application name which is
taking up page faults, then do a search in Windows Explorer for a program
with the same name. When you find it, consider renamed it from "process.exe"
to "process2.exe".
I just found that Sony Picture program (that came with Video Camera) was
causing my laptop to slow down horrendously, and I never used it. It just
ran each time I started my computer... Worth a try, before you spend $100 on
another 512MB of RAM.
PS More RAM will always speed you up a little. I'm just suggesting a few
things so you can figure out if it is necessary.