I have a Compaq laptop which currently has Vista Home Premium 32 bit installed. The machine has 2GB Ram. When I ran the Crucial memory scanner it indicated that 2GB was the max my machine could have. I have pre-ordered Windows 7 HP. It comes with both the 32 bit and te 64 bit version. As I am planning a clean install I could install either equally easily. However my worry is this - according to Microsoft the minimum requirement for the 32 bit version is 1GB of RAM, which my system easily exceeds, while for the 64bit version it is 2GB of RAM, which my system just meets (my processor is a 64bit core 2 duo).
My question is basically this due to the limitation of RAM would the 64 bit version of Windows 7 run more slowly than the 32bit version?
They would run about same speed, x64 will use more RAM so You will have less RAM left for other soft and You will run out of RAM sooner this is when it will become slow when it has almost all RAM used.
There is no reason to install x64 if You have less then 4GB RAM considering that x86 have better compatibility with software and drivers.
Which laptop do you have? Most of Core 2 Duo laptops should be able to acept 4GB RAM an use at least 3GB of them.
I would suggest that you use the 32 bit version as you will have less resources used (background services running) and the overall performance and experience would be better than the 64 bit version. There would be a large difference in the performance of the 2 Operating systems as the 64 bit version utilizes more ram and has more services running at all times VS the 32 bit version.
I disagree there is a 'large difference' between 32 and 64 bit operation with 2GB of memory - I've run both (Vista), and from personal experience will say the differences as far as user experience are minimal.
Having said that, 64 bit registers are larger and Win 7 64 does have the services related to WOW64 running in addition to the 'normal' 32 bot ones. So it's memory footprint is a little larger. If/since you're limited to 2GB of RAM I would stick with Win 7 x86 (32 bit) for this reason.