How to Backup Windows Registry – XP, Vista and Windows 7
Windows registry stores the most essential information concerning your computer. The registry holds information of hardware and software installed and other related data. How Windows is configured during setup and every time new hardware and software are added also saves in the registry. In fact, big or small changes you made on computer will reflect on that part of the system data – the Windows registry.
It is very important to keep a backup of Windows registry just in case anything goes wrong. With latest operating system, this process is integrated already to System Restore. It covers not only backing up of registry but the entire system in general. Saving your registry for the purpose of reviving your system from software and hardware failure is not sensible anymore. As long as you enable System Restore, it can do that task.
Backing up the registry serves for a specific intention. If a virus intentionally modify part of it to block your access to certain services, then restoring only the registry saves you time. You don’t need to go through the whole system restore process.
How to Backup Registry on Windows XP, Windows Vista and Windows 7
1. For Windows XP: Click Start > Run, and type regedit in dialog box and press Enter.
For Windows Vista/7: Click Start >Search program and files, type regedit and press Enter.
Note: You must have administrative privilege to perform this.
2. If it prompts if you want to allow the program to make changes on the computer, click Yes.
3. Windows registry editor will open. You can backup the whole registry or just a part of it.

Windows Registry Editor
4. On file menu, click on Export.

Export will save the Windows Registry to an assigned destination.
5. Select proper location where you want to save the backup. Then click Save. It will have a .reg file extension.
You are now keeping a backup of registry. To restore, simply repeat the process but this time you have to execute the Import command.
Red54
Oct 22, 2009 @ 22:50:30
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Bob Bobson
Apr 29, 2012 @ 20:58:28
Exporting a .REG file is certainly easier, especially since it is in human-readable form that can be edited and compared. However, for a full backup, boot into a different OS (even DOS would do) and copy the whole registry hive file (System32\Config\*, %userprofile%\ntuser.dat, etc.)