Hello. I was recently given a Dell Optiplex 755 Mini Tower with no hard drive in it, The sticker on the bottom of the machine says it was running Windows Vista Business. I plan to put a new hard drive in it and re-install Windows Vista Business. I am trying to figure out if I need to get the 32 bit version or the 64 bit version.
I have done a bit of research and from what I understand I could install the 32 bit version of vista on either the 32 or the 64 bit processor, correct?
But I have also read that the product key on the Vista sticker will be specifically for either the 32 bit version or the 64 bit version. I would like to make sure that I install the correct version of Vista Business so that I am able to use the product key from my sticker.
Any info would be greatly appreciated. Thanks.

Just as an aside Fastfifty may I ask if the Vista Business disk came with the Optiplex, even though it has no hard drive or are you planning to buy a new retail copy of Vista Business?

If it is the latter case then it will come with its own key that you can use.

Every processor can handle 32bit information, 64bit requires a core2duo or higher for intel processors. I always install 32bit operating systems, I always found 64bit slow even though it should be theoretically faster, must be just me.

It did not come with a disc and I wasn't planning on buying a retail copy either. A friend told me he could download and burn it for me to use, but that I need to tell tell him whether I wanted the 32 bit or the 64 bit version.

Dell 745 w/Q6700 geekbench 32 bit @ 4900+ 64bit @ 7590...use 64 bit
http://browser.primatelabs.com/geekbench2/1111369