How to identify 32 or 64 bits -

[Bob Goodwin]

    Can someone tell me how to determine if a computer can run 64 bit
    Fedora?

    I have two similar Dell desk top computers with what appears to be
    the same processor, one of which has had F-12 64 bit installed on it
    and seems to be happy. I always assumed they were 32 bit computers
    and really don't care which they are but wish to avoid using the
    b.w. to download another copy of F-12.

    I need to know before I can upgrade the second one.

    Thanks.

    Bob