Investing in an Athlon 64 PC for 64-bit Windows allows for the installation of 32-bit applications, although they may run slower. The primary distinctions between Win64 and Win32 involve pointer variable sizes and virtual address space, but both can support 64-bit file addresses under NTFS. There is skepticism about the necessity of 64-bit systems for home users due to limited software availability, with a suggestion to wait until 2008 for broader adoption. The upcoming Windows Longhorn is expected to offer more capabilities than the 64-bit Windows XP, which is projected for late 2005 to early 2006. Additionally, hardware drivers must support 64-bit to function properly in a 64-bit OS. Current processor speeds around 2.6GHz are considered optimal, with AMD options providing good performance at lower costs.