In the geek world, Vista tends to be a divider, not a uniter and one of the main points of contention continues to be the question of how much RAM is enough. Some folks (most of whom reside in a place called Redmond) will tell you that 512MB will get the job done while others find that 4GB is required for optimal performance [1]. Since reading up on the issue, you may have tried stuffing 4GB of RAM in your system, only to find that it won't recognize the full amount. Surprise! If you think back to your freshman year computer science lectures, you'll recall that a 32-bit operating system can only address 32-bits of memory at a time, which means a theoretical limit of 4GB--however, after the memory reserved for video RAM and the BIOS is used up, you're left with just over 3.5GB [2]. The solution? Get the 64-bit version of Vista, of course. No one said this upgrade was going to be cheap.