[H] Vista 64 question

[Scott Sipe]

I have a dell with a Q6600 processor and 2gb ram. It has 32-bit Vista  
Home Premium.

Two questions:
1) Do I gain anything by installing Vista 64-bit on it? Is there an  
actual performance difference?

2) Can I use my current Vista Home Premium license number to install  
the 64-bit version?

Thanks,
Scott