Slitherine

I have installed Field of Glory, as well as the battle pack and 2 other scenarios. The problem I am having, right from the beginning is that I have to restart my computer every time I want to play the game. How do I fix this? Thanks.

Can you be more specific?

When I click the Field of Glory icon, the opening screen comes up. However, when I click "Play", nothing happens. However, if I restart my computer, the game will start when I click "Play". After playing the game for a few days, it reverts back to not starting when "Play" is clicked.

You don't shutdown your Windows everyday?

Never have.

You should, at least do a reboot each day.
Maybe it's a 3rd party program which interfering with the normal starting of the game.
The easiest way to identify which program is causing this, is to disable all background programs by running msconfig and disabling all non-windows start-up programs and services. The problem is that you need to reboot Windows once you use msconfig, so you won't be able to identify it.
My suggestion is for you to reboot your Windows more frequently.

Ah, but that doesn't totally solve the problem. As I mentioned earlier, when I restart, it will play for awhile and then won't.. Now what??

I'm sorry, but could you please be more specific with it will play for a while and then won't?
You mean the game will crash when you are playing a game?

No. What I mean is that I can play different times and days for awhile. Then it won't start again.

Clearly there's something wrong with your system, but unfortunately there's no way for us to diagnose it. Maybe it's something related with a 3rd party program interference like I have said.
My suggestion is to reboot your Windows everytime you experience the issue, as it seems allow you to play when you do this.

I guess I'll have to do just that. However, this is the only game, including other Slitherine games, that has this proplem.

Sure. Still, it's something specifically related with your system that is causing this.
Please note that different programs do different calls to the system, so that explains why you can have a problem in one and not in the others.
Whatever is interfering with the game is clearly not interfering with other programs.