how can i run CF on windows 64 bits?

There is no x64 version of cf, but Windows x64 can run most x86 programs no problem. I do it on my machine. What specific error are you getting?

I'm running it on mine. It should be set up so that Windows automatically runs it with the proper compatibility settings. If you right click on the Crossfire shortcut and go to properties, the "compatibility" tab in the properties setting will have a "compatibility mode" section. In that section you can click on the box to run in compatibility mode with an earlier version of Windows, mine appears to be set to run as it would with Windows XP(Service Pack 2).

There's another option somewhere, I have no idea where, that you can select so that programs will automatically choose their best compatibility settings. You have to manually select this option otherwise your version of Windows tries to run it according to its own settings(64bit etc).

Maybe someone else can elaborate a little more on that.