Definitely
Virtually all AMD CPUs Single, Dual, Triple and Quad Core are 64bit ( except for the low power Geode and some old Semprons and Athlon XP and below ).
Most Intel CPUs are also 64bit capable ( except for some Pentium Ms and anything P4 and below - 775 P4s were 64bit capable but they were really bad ).
Please give us your full specs and we'll make sure you're good to go