Operating System Installation Question (PC)

[vladittude0583]

Hey guys, I currently have Windows XP Home installed on my desktop, but I am thinking of purchasing either Windows Vista Home Premium or Windows Vista Ultimate, preferably the latter. Anyhow, my desktop supports 64-bit processing and I am interested in the 64-bit OS primarily for future purposes in case I encounter more intensive applications in the not too distant future. However, I am not a computer programmer or some software engineer, therefore, I was wondering if I actually have to tweak settings on my actual desktop itself to configure it to run as a 64-bit OS? Also, are there really any advantages to having a 64-bit OS since I keep hearing that most software right now is 32-bit? I currently have Windows Vista Home Premium factory installed on my laptop and my experience with it is just about the same with the Windows XP on my desktop, however, I have yet to utilize a system that ran Windows Vista Ultimate (either 32-bit or 64-bit). What would you guys recommend?

Some specs of my desktop:

Intel E6850 Dual-Core @ 3.0GHz per Processor
nVidia GeForce 8800 GT
nVidia nForce 680i SLI motherboard
4GB of System RAM running @ 800MHz Corsair Hi-Performance
2x320 GB Hard-Disk Drives