Out of curiousity, my copy of Windows 7 is 64 bit, I am well aware of what the differences and I know this does not make much sense, but out of curiosity could I install a 32 bit operating system on a CPU that says 64 bit certified, I am wondering because my buddy recently used an old copy of windows xp cause he hates 7, I could have sworn his Windows 7 was 64 bit and then i looked on his xp and he has a 32 bit, everything seems to run fine except Steam games and belive we have tried every steam forum help possible to no luck so i was just wondering if it was possible that his old os was 64 bit and he installed 32 bit and that might be whats causing the problems. Thanks
64-bit Intel and AMD processors have a 32-bit mode in which they are identical to a 32-bit processor (in just the same way that they - and 32-bit processors - have a 16-bit "real" mode that makes them the equivalent of the original 8086). But it does mean that you are not using about 66% of the potential of the processor. It's a bit like having a V8 and then pulling the spark-plug leads off 5 of the cylinders.
So, yes, you could install a 32-bit OS on your PC.