Good news if you need not to do anything because you can just point to vhd file and the virtual machine is able to run. Unfortunately if you have installed Virtual Machine Addition from Windows 7 then mostly likely your mouse will not function in your virtual machine. You need to uninstall the Virtual Machine Additional with using mouse. Your question now will be how to reach control panel without using mouse. It is easy for you to get to cmd with using the mouse. Then from cmd type appwiz.cpl.