If you use Infopath Client, here a some C# code to know the major version of office:
using Microsoft.Office.Interop;
string sVersion = string.Empty;
Microsoft.Office.Interop.Word.Application oApp = new Microsoft.Office.Interop.Word.Application();
oApp.Visible = false;
switch (oApp.Version.ToString())
{
case "7.0":
sVersion = "95";
break;
case "8.0":
sVersion = "97";
break;
case "9.0":
sVersion = "2000";
break;
case "10.0":
sVersion = "2002";
break;
case "11.0":
sVersion = "2003";
break;
case "12.0":
sVersion = "2007";
break;
case "14.0":
sVersion = "2010";
break;
default:
sVersion = "Too Old!";
break;
}
MessageBox.Show("Word Build: " + oApp.Version + System.Environment.NewLine + "Word Version: " + sVersion,
"Office Version", MessageBoxButtons.OK, MessageBoxIcon.Information);
object a = (object)false;
object b = (object)1;
oApp.Quit(ref a, ref b, ref a);
oApp = null;