Hello, My system is Athlon 64 X2 based and using Ubuntu 9.04. The uname cmd gives this: Code: Linux blueshift-desktop 2.6.28-11-generic #42-Ubuntu SMP Fri Apr 17 01:57:59 UTC 2009 i686 GNU/Linux I downloaded some amd64 architecture based packages from Ubuntu site. But it says 'Wrong architecture amd64' when i try to install. The corresponding i386 architecture version is installing without any problems. Also the same i386 package is giving similar error about architecture on my friends system which is Intel DualCore based. Why is their architecture mismatch? Why does it not supoort amd64 packages?