i downloaded fallout 3 GOTY edition off steam and it is completely dowlnoaded. but when i click it it brings me to the pop up that says " Play, Options, Data Files etc" and when i press play it just goes away and nothing happens. can someone tell me why and help me?

We need information on your computer specs

please run diagdx.exe and post the results in spoiler tags.

im sorry how do i run that?

start and in the search field type dxdiag.exe. I think I had the wrong command. I do not know if that works on Windows 8 since I have never used that OS.