remove registry data. To remove a key (and all subkeys, values and data), the key name must be preceded by a minus sign ("-"). For example, to remove the HKLM\SOFTWARE\Foobar key (and all subkeys, values and data), [-HKEY_LOCAL_MACHINE\SOFTWARE\Foobar] To remove a value (and its data), the values to be removed must have a minus sign ("-") after the equal sign ("="). For example, to remove only the "Value A" and "Value B" values (and their data) from the HKLM\SOFTWARE\Foobar key: [HKEY_LOCAL_MACHINE\SOFTWARE\Foobar] "Value A"=- "Value B"=- To remove only the Default value of the key HKLM\SOFTWARE\Foobar (and its data): [HKEY_LOCAL_MACHINE\SOFTWARE\Foobar] @=- Lines beginning with a semicolon are considered comments: ; This is a comment. This can be placed in any part of a .reg file [HKEY_LOCAL_MACHINE\SOFTWARE\Foobar] "Value"="Example string" Group policies Windows group policies can change registry keys for a number of machines or individual users based on policies. When a policy first takes effect for a machine or for an individual user of a machine, the registry settings specified as part of the policy are applied to the machine or user settings. Windows will also look for updated policies and apply them periodically, typically every 90 minutes. Through its scope a policy defines which machines and/or users the policy is to be applied to. Whether a machine or user is within the scope of a policy or not is defined by a set of rules which can filter on the location of the machine or user account in organizational directory, specific users or machine accounts or security groups. More advanced rules can be set up using Windows Management Instrumentation expressions. Such rules can filter on properties such as computer vendor name, CPU architecture, installed software, or networks connected to. For instance, the administrator can create a policy with one set of registry settings for machines in the accounting department and policy with another (lock-down) set of registry settings for kiosk terminals in the visitors area. When a machine is moved from one scope to another (e.g. changing its name or moving it to another organizational unit), the correct policy is automatically applied. When a policy is changed it is automatically re-applied to all machines currently in its scope. The policy is edited through a number of administrative templates which provides a user interface for picking and changing settings. The set of administrative templates is extensible and software packages which support such