Q:
A: I will use Windows Vista Home Premium as an example. The 32-bit version can only except up to 4GB of RAM and has other limitations. While the 64-bit version can have virtually limitless RAM, and doesn't have many limitations. 64-bit OS requires a CPU that can support a 64-bit operating system. A major downside to it though, is that some programs can't function on a 64-bit system. Unless you are an extreme power user, and are planning on adding more than 4GB of RAM, there is no point in getting a 64-bit OS. If you do want more RAM and are a power user, you can mail to Microsoft for a free 64-bit version of any retail copy of Vista Home Premium or Home Basic, while Vista Ultimate comes with a 32-bit and 64-bit version on the one disc.