The Windows registry has been around since the 16-bit editions of Windows, and will continue to be a key component of the operating system even after Windows Vista Service Pack 1 and Widows XP Service Pack 3, and even after Windows 7. However, this does not mean that the registry, as well as additional Windows components, have stood still. The registry has in fact evolved along with the Windows platform. At this point in time, with both XP SP3 and Vista SP1 closing in to their respective RTM dates, Microsoft has not informed of registry changes to be implemented with the two service packs.

One illustrative example in this case is the growth of the registry hive. "Back in 16-bit Windows, the registry was a very different beast. Originally, the only registry hive was HKEY_CLASSES_ROOT, and the only things it was used for were COM object registration and file type registration. (Prior to the registry, file type registration was done in WIN.INI, and the only verb you could register for was "open".) The registry was stored in a single file, REG.DAT, which could not exceed 64KB in size," explained Microsoft's Raymond Chen.

The registry hive has expanded considerably since just the HKEY_CLASSES_ROOT. Now, operating systems, such as Vist,a feature standard hives such as HKEY_CURRENT_CONFIG, HKEY_CURRENT_USER, HKEY_LOCAL_MACHINESAM, HKEY_LOCAL_MACHINESecurity, HKEY_LOCAL_MACHINESoftware, HKEY_LOCAL_MACHINESystem and HKEY_USERSDEFAULT. "A hive is a group of keys, subkeys, and values in the registry that has a set of supporting files containing backups of its data. The setup phase of the Windows boot process automatically retrieves data from these supporting files," Microsoft informed.

The registry is a central hierarchical database specific to a variety of Windows operating systems, playing a critical role in storing information related to user accounts, installed programs and the hardware infrastructure, as well as the configuration of the operating system. One aspect of the registry that Microsoft might scrap from Vista SP1 to Windows 7 is Registry Virtualization.

"Registry virtualization is an application compatibility technology that enables registry write operations that have global impact to be redirected to per-user locations. This redirection is transparent to applications reading from or writing to the registry. It is supported starting with Windows Vista. This form of virtualization is an interim application compatibility technology; Microsoft intends to remove it from future versions of the Windows operating system as more applications are made compatible with Windows Vista," Microsoft added.