Why won't my 64 bit computer will not run 64 bit games?

I have lenovo y580 laptop with Windows 7, 64 bit, but for some reason I can't run 64 bit games.

I first discovered this problem while I was trying to play the new Everquest game: Landmark.

The download and install goes fine but when I press play the.exe opens for about a second and then closes.

I searched through the forums and everyone said that if the.exe is failing like that, it is because you have a 32 bit operating system, which I do not.

I contacted customer support and they could not find the problem so I was stuck. After many hours of trying different things I finally gave up.

I recently downloaded another game and when I open the launcher it has a check box to select if you wish to use a 64 bit client. The box was already selected so I closed the options and pressed play.

The.exe opens for a second then closed. Just like landmark did.

I opened the launcher again to see if it worked if I unchecked the box to use a 64 bit client and the.exe opened fine and I could play the game.

I'm confused why my 64 bit computer refuses to run 64 bit games? Anyone else ever have this problem?

Click start button (right hand bottom corner of screen)
right click on computer
click properties
is it 64 bit?

Have you triple checked that your OS is 64 bit?