What are the hardware requirements of Linux? and what processors does Linux run on?

Linux will techinically run on pretty much any hardware, from 386 onwards (in the Intel range), as well as some Macs (YellowDog, Mandrake-PPC), etc. I have read something about getting it to work on i286 (but not 8086s). It'll run on Sparcs, Alphas, DECs (I'm not quite sure about the distinctions between these as I've only ever used it on an Intel based system). Sometimes, however, you may need to install it onto another system first, manually configure the kernel for the new system and then install onto the new system.

There is normally a readme file (or something) that's on the installation CD that should tell you what basic system that particular distro requires.

your going to also want to check compatibilty lists on whatever distro your using, some come with drivers that others don't have included yet and vice versa...
its a good idea to check out distro of choice, what it comes with and then what those support, hardware that is...

probably the biggest problem between linux and computers-off-the-shelf would be the winmodems, which aren't true modems, but stripped down versions. almost all new systems seem to use these, and few are supported on linux. usually the best solution is to get a real modem. other than those, most hardware is supported.

no one mentioned amd yet, which is intel-compatible, and is also supported.