Hi John, welcome to NST
Does the laptop still have the hidden Sony recovery partition ?
Check here how to find and use it to factory reset the laptop back to "out of the box" condition.
If it's been wiped along with Vista, then you could either buy yourself a Vista DVD, or try borrowing one from a friend and installing a vanilla Vista system, using the serial number on the laptop not the one on the DVD.
The processor in that PC supports 64 bit OSs, but I think it came originally installed with 32 bit. I don't know how the setup program handles 32/64 when you quote the serial number, I have an OEM system builder copy which is exclusively 64 bit, so I have no experience of the "full retail" which comes with both flavours included.