Windows XP includes performance improvements such as fast boot / logon / logoff, fast application launch, CPU simultaneous multithreading, new NTFS version NTFS v3.1 and so on. Windows Explorer also gets new features and changes, like task pane (useful file actions shown in the left hand sidebar), file thumbnails, sorting, grouping etc.
The Start menu gets two columns, and now it is completely customizable by the user. The appearance of windows shell elements such as desktops, taskbar, start menu, get a better design with transparent icons and shadow drops. Windows XP has a lot of updates in the user interface (compared to Windows ME and 2000), making it easier to use and navigate through files and programs. Windows XP Professional X64 support WoW64, a Microsoft technology that allows 32-bit capable software applications to run on a 64-bit Windows operating system.
The main advantage to use the 64-bit operating system is to allow 128 GB of RAM in PC, while the 32-bit OS can only support up to 4 GB RAM. Windows XP Professional X64 is a edition, and the 64-bit version of the Windows XP operating system released publicly on April 25, 2005. Features on this version of Windows are similar to Windows XP Pro 32-bit, the advantages of 64-bit OS will be additional only.