Windows 7

Change Product Key
Open the command prompt ensuring it is run with administrator privileges

Now type following command

slmgr.vbs -ipk 

Note: Ensure you enter the code with hyphens

To activate windows after changing the key, type the following

slmgr.vbs -ato

Display All Icons (Classic View) In Control Panel
Start menu

Type gpedit.msc then press enter

In the left hand pane click through 'User Configuration' --> 'Administrative Templates' --> 'Control Panel'

In the right hand pane double click on 'Always open All Control Panel Items when opening the Control Panel'

Select 'Enabled'

Enable Secure Logon (Ctrl+Alt+Del)
Start menu

Type netplwiz then press enter

On the resulting window click on the 'Advanced' tab

Check the box next to 'Require users to press Ctrl+Alt+Delete

Click 'OK'