Here is a range of stuff I'd try, in rough order I'd try it in. (I.e., I'd check if Aces High runs after each of the steps.) Don't do any of the steps you aren't reasonably comfortable with -- botching the following could mess up your system more than it is messed up now.
Did you overclock your video card or computer? Set it back to normal settings (or even underclock it) and see if things work.
Check that your fan in your computer and on your graphics card (if it has one) are working.
Uninstall any low-quality utilities that might autostart when you boot up Windows and that you don't need. Disable or turn off any other software that is running in the background just while you do a test run with Aces High to see if any of them might be the problem.
Install the latest video driver. Get it not from your OEM card manufacturer but straight from the Nvidia or ATI site (depending on whose graphics chip you have).
Install the latest sound driver. Again, get it from the maker of the chip (like Creative), not whoever made the card (unless the two are the same).
Flash your motherboard BIOS up to the latest level if that is easy to do (such as if you have a Dell, where Dell makes latest BIOS updates easily available). Especially don't do this if you aren't sure what you are doing.
Uninstall and reinstall Aces High.
If crashes are happening for more than Aces High, unplug your computer, make sure you touch metal case in your computer (to get rid of static on you), and physically unplug and replug all of your cards in your computer (to make sure they are all seated correctly). See if anything doesn't look right. I wouldn't do this, though, unless my computer were crashing in every application, not just Aces High.
If none of that works, for me, it would be time to wipe my computer clean and reinstall the OS and drivers from scratch. Back up whatever you don't want to lose first, of course.
