computer ran out of available memory?

FSX is a 32 Bit process. It will only address 4 GB Virtual memory address space (not to be confused with installed RAM).

Unfortunately half of that is reserved for system dlls (kernel32.dll, GDI32.dll, user32.dll etc…) and drivers.

That means only 2 GB is available for FSX, the loaded aircraft add-on, scenery, weather, AI traffic and other add-ons.

We build voice control add-on for FSX & FS9

In early days we were tempted to load our software (which happens to need a memory hungry speech engine) inside FS9 (or FSX) process via fsInsider.dll, the dll that gets loaded when the sim starts.

Doing that would mean at least 300 to 400 MB less virtual address space available to other add-ons.

In the end we decided against it.

Only a few megabytes (less than 10) are needed by the dll running in the sim to read from and write to the sim.

The bulk of the software runs in a separate process (with its own 4GB available virtual address space).

Should the speech engine leak memory, or our software misbehave the separate process would eventually die, but should never compromise the integrity of the flight.