Well, I downloaded the free version, set most of the programs that I eventually settled on to be closed down, added the TRS2004 shortcut from my desktop to the Game Box, and then ran it. It does free up some memory, which, since this laptop only has around 896 megabytes of RAM in it, is a good thing.

There might have been a little better performance in Trainz, but no thing major yet. However, every little drop of extra memory, etc., counts on this laptop. And besides, I had not switched off a few programs using Game Booster that I eventually did settle on after running Trainz, which included the Desktop Window Manager, Dell Webcam Manager, etc., which frees up a little bit of space.
Overall, I still need to upgrade the memory in my laptop, but this program does free up some memory. Maybe I can increase the size of the Trainz resource cache (the memory that Trainz uses for caching stuff so that it does not have to load it each time you view e. g. a certain section of a map again) a little more, which will likely increase performance by a little.
I do not really know what the other features in the payware version do. I do not think that I will spend the 10 bucks on the payware version yet. Those 10 bucks could go toward the price for an other gigabyte or more of memory.
Any way, I think that I will run Trainz with the Game Booster from now on.
Regards.