virtualbox.org

Im running windows 7 pro x64 as my host OS using intel cpu 3GB ram.....
In virtualbox i do not have the option to install a guest os running 64bit??? trying to install win server 2008 r2 x64 as my guest os.
Im using the latest virtualbox 4.1.20
CPU is pentium dual core T4200

Your CPU does not support VT-x which is needed to run 64-bit guests.