32 bit or 64 bit

Hi John.
Sorry for the selective quote here, but the limit of a 32-bit system is 2GB of addressable RAM, not 4GB.
Whilst it is possible to install 4GB of RAM in a 32-bit system, no application will ever be able to access more than 2GB, and the switches added into the INI file are a fudge, probably leading to system instability in the long run as it will remove allocations made by the system for expansion cards & other devices.

@Gerry.
It is indeed true that the only difference is access to more RAM - however, and this is important, there are subtle implications that make this worthwhile even if you do not use large ROMpler libraries. Since the advent of 64-bit, programmers have got even lazier in generak as there is no longer any pressing need to optimize memory footprints so they simply quote ever larger amounts of memory needed as “recommended” or even “minimum” requirements.
Additionally you will find a general improvement in access times for a lot of things, plus you will find you can do more before hitting those brick walls of no more memory available. If you do go 64-bit, and I recommend it even though the actual audio is no better in terms of quality, there are things you need to look out for.
The main one is to ensure your VST2 plugin paths are not picking up both 64 and 32 bit versions of the same plugins.