My CPUs - 64 or 32 bit?

[Bobbler]

Thinking of going Vista but I have two machines that are Intel based. I am not really used to Intel based processors (been with AMD since AXIAs and Thunderbirds ) so unsure if either of them are actually 64bit based.

Just want to confirm if either of these CPUs are 64 bit to help aid in my choice of Vista package to go for:

T2500 Core Duo
Pentium 4 531

I am hoping the Core Duo is most likely as its the newer processor type I think and its also the "best" of the two systems I have (more ram, better graphics etc)

Edit:
Put the wrong P4 code in

 

[Bobbler]

T2500 no
P4 521 yes

Thanks muchly Mr Paul.

Damn it. Wonder if I can swap the CPUs around..
Will have to investigate that as the P4 based box is very basic as I just use it for downloading, burning CDs and remote desktop to work - onboard graphics, 512MB ram.
The T2500 is my laptop (Dell M1210) which has better specs.

 

[Bobbler]

you're only supposed to install 1 copy of vista on 1 machine aint you? tut tut hope ** not going to break laws by breaking the EULA !

LOL. No one said anything about installing on more than one machine with one copy, except you

I already have two licenses for XP home (one retail, one came with my laptop) and I just trying to decide which one to upgrade to Vista. I was thinking the 64 bit platform would be more future proof so when choosing the version (would be retail so I dont have it limited to one motherboard like the OEM, which wouldn't be a great idea with a laptop) I would take that into account.
I cant afford two licenses for Vista Ultimate at the moment.

Looking like the laptop would be the best option then really.

Thanks for the info, this has turned into more of a software post now LOL.

Looking at the spec of the PC vs the Laptop I cant do anything with the CPUs as they are different sockets anyways