First time poster here, I've got my first Linux problem before I even have it installed...
I'm sure that my CPU is an AMD Athlon XP 64 or something similar to that (if there's any way I can produce accurate information regarding this let me know if that's necessary). I tried installing FC2 x86 earlier tonight, which I understand requires a 64-bit processor, but immediately an error saying my CPU does not support "long mode," and that I need a 32 bit distribution. Which is a little frustrating . I hope I actually do have a 64 bit processor, and that somebody can tell me why FC2 doesn't like it... help me, please!

welcome to LQ.

"XP" and "64" is a contradiction, at least in AMD terminology. double check to see if you're not running an Athlon XP instead of an Athlon 64. you can check in the BIOS or in whatever other OS you're using.

seems you may still boot to your existing window OS:

(Under XP...)

My workstation icon:

right click on Properties:

mine, Displays:
AMD ATHLON (TM) 64 PROCESSOR
3200+
2.04 GHz
XX Go of RAM

...
beside, I am still looking for an easy AND FREE to install distro...
???