Technically you could, however you would not have an activated copy of Windows as you would have no Vista key for the Inspiron 530.
I have a Inspiron 530 Desktop that is running Windows XP & i have a Windows Vista CD that came with a Inspiron N4010  Laptop that i had Windows 7 install on from the factory.  My question is can i install the Windows Vista CD on the Desktop to replace the Windows XP OS?
Vista