i have a problem installing arcgis server 10.2, i installed arcgis desktop 10.2.1, But when trying to install arcgis server it said that it wont be installed until i upgrated this list of product to 10.2, but i get empty list. i have a 64bits machine, and my arcgis for desktop is installed on program files (*86) could it be the source of the problem?
You cannot have different versions of the ArcGIS Suite installed on the same machine. You already have Desktop 10.2.1 installed, so you need to install Server 10.2.1 or uninstall Desktop and reinstall the 10.2 version. As a third option, install Server on a different machine.
I assume the reason you receive the blank list of software that you "need to upgrade" is because the installer sees that the server version is different from the installed version of Desktop and is smart enough to realize that Desktop is not a lower version so doesn't list it (though not smart enough to give you an error message that makes sense for your situation).