My card's only 128MB and I'm running right now with 1GB of DDR400 RAM
You've got a problem with your install.
If you haven't installed anything else, I'd do a system restore up to when you installed FSX.
Then reinstall all of your system drivers (motherboard and graphics).
Then start over. If you've you've got damaged drivers before you install FSX you won't have a cat's chance of making it run and there's no point trying to salvage what is obviously a mess.
Do what I've said and start over. It'll be less pain in the long run and although you might not see fantastic performance (er change that to 'ytou will not...') you should at least be able to get it to run.
Heck, why should you be let off so easy when we're all getting so much pain...