I'm very grateful for all replies. I have implemented Stacy's formulae as a test, and am awaiting response. I am still digesting Ed's discourse!

I note that without any specification of memory to be used, VFP allocates the same amount of memory from the same physical memory size under both Win95 and Win98 (about 48Mb from 64Mb foreground). I can't say what it does under Win2000.

My particular apps don't use large tables - the maximum number of records in any table is around 20k. For this reason, I tried the formulae as above.

It struck me that for a user who is running an installed exe (Runtime VFP only), you cound use the CONFIG.SYS file to specify memory allocation outside the program. Then if you need to tweak it, you just edit the config file. I tried

COMMAND = store sys(3050, 1, 16000000) + sys(3050, 2, 8000000) to fred

in the file; it seemed to work. There is a use for the 'store' command!

I'll try the dynamic formulae next to make it more general.

Thanks to all again

Mike