Yush. Just like it has been said here. Be sure you have a 64-bit CPU. That's the first thing.
Other thing is that you can't have both 32 and 64-bit OSs. Either you format the whole HDD, which is the better option, or installed the 64-bit OS on the same HDD and the setup will move the old windows into a "windows.old" folder, leaving you with all your old files and such.
You'd be best off if you backup first, or at least save any personal files and such on a removable HDD or a flash drive first, then format the HDD and do a clean install for the 64-bit. That way there wont be any issues later on.