Once you upgrade to a proper 64-bit OS (Windows 7, Windows 8.x, 64-bit Linux, etc.), you will be able to use well beyond 8GB of

One note to anyone using a 32-bit OS, such as all Windows XP editions except for "Professional X64" or "Itanium," will not benefit from this upgrade, since the maximum amount of RAM those can address is 3.2GB or 4GB of installed RAM.This is not just a Microsoft limitation, but inherent to all 32-bit operating systems, including older version from Apple and even 32-bit Linux and other Unix-like systems