Changes made to the Windows registry happen immediately, and no backup is automatically made. Do not edit the Windows registry unless you are confident about doing so.
Microsoft have issued the following warning with respect to the Registry Editor:
"Using Registry Editor incorrectly can cause serious, system-wide problems that may require you to re-install Windows to correct them. Microsoft cannot guarantee that any problems resulting from the use of Registry Editor can be solved. Use this tool at your own risk."
How to open the registry editor
At the taskbar, click Start | Run | Type:
regedit.exe | Press Return. The registry editor opens.
How to back up the registry
Before you edit the registry, you should make a backup (i.e.backup the current settings).
- Open the Registry editor.
- On the 'Registry' drop-down menu, click 'Export Registry File'.
- In the Export range panel, click 'All', then save your registry as Backup.
How to change permissions in the registry
This is described in the knowledgebase article: Applying permissions to a Windows registry key .