Using a Dell reinstallation disk for Windows Vista on a Sony laptop
The DVD that comes with a Dell is a normal Windows Vista DVD. It will work on any PC. However, you cannot use the license that came with the PC; that cannot be transferred.
It depends - I have had mixed results. Typically, it should work but the licence may be invalid and even if you type the correct one from underneath the laptop, it may still not work.
Providing this laptop did have Vista at one point, you are best off trying to create a recovery disk or asking Sony for another copy and it should install without even asking for licensing details.