I had a virus, so I did a destructive system restore, which reformatts the hard drive and reinstalls all the things that came with the computer. As I've been reinstalling my programs, occasionally I've had some minor problems with Windows Installer. Not a big deal, but when I went to install FSX, it came up with an error. The first screenshot is this error. So I turned off my virus protection, and tried again. No luck. I cleaned the disc off and tried to install it again. No luck. Then I remembered my problems with Windows Installer, and updated it. Problem solved. Then I went to install Acceleration. Same problem. I repeated the same steps, except for updating Windows Installer, because it was (obviously) already updated. The error from Acceleration is the second screenshot. Thanks for the help, in advance!
http://www.mediafire.com/?43kpbzy2ni2
http://www.mediafire.com/?opxinyepojo