I've recently downloaded a couple files. One is a game (from GOG.com), another a BIOS update (from Dell), among others. When trying to open either of the two above, I get the following error message:

"The version of this file is not compatible with the version of Windows you're running. Check your computer's system information to see whether you need an x86 (32-bit) or x64 (64-bit) version of the program, and then contact the software publisher"

Another recently downloaded program gives me a checksum fail type of error message.

I've kept up to date with Microsoft updates, and have tried running them in various compatibility modes, but get the same message each time.

Any help or insight would be greatly appreciated, as I am rather significantly tech illiterate. Thanks!

Computer: Dell Alienware M15x
Processor: Intel Core i3 CPU, M350 @ 2.27GHz
RAM: 3GB
OS: Windows 7 Home Premium (64-bit), (Service Pack 1)