How to tell if a new PC with 64 bit has vista 64 bit?

Try right clicking on Computer on the desktop, go to Properties, and it should list there whether the operating system is 32 bit or 64 bit.

If it says 64bit, then you're running Vista x64.

Wait i dont understand are you trying to figure out if the version your getting is 64bit or if your trying to figure if your computer already has 64bit?

Edit

Oh now i see what you mean. If you could possibly post a link to the computer we could tell you maybe.

Just to add, if you are buying the pc in-store, chances are very good it's 32-bit.

Although Vista 64-bit works extremely well, it isn't quite mainstream yet, it's the hardcore set that are usually running it. If you are buying a pre-built online, you usually have the opportunity to select your OS of choice (so obviously then you would know).

Here is the link, http://www.circuitcity.com/ssm/HP-Pavilion-Desktop-PC-A6120N/sem/rpsr/oid/185191/catOid/-rpem/ccd/productDetail.doVaioAS

link doesnt work