Read and Write in registry from c#

Before start to learn how to edit the registry a quick 
Open Registry window
1) Press CRTL+ R
2) run window will open.
3) type command "regedit"

4)and press enter , below window get open

Come back to original topic

.Net provide the class RegistryKey it is in Microsoft.Win32 namespace

below is the types to read different base key

• ClassesRoot
• CurrentConfig
• CurrentUser
• DynData
• LocalMachine
• PerformanceData
• Users

ClassesRoot :   Defines the types (or classes) of documents and the properties associated with those types. This field reads the Windows registry base key HKEY_CLASSES_ROOT.

CurrentConfig : Contains configuration information pertaining to the hardware that is not specific to the user. This field reads the Windows registry base key HKEY_CURRENT_CONFIG.

CurrentUser : Contains information about the current user preferences. This field reads the Windows registry base key HKEY_CURRENT_USER

DynData : Contains dynamic registry data. This field reads the Windows registry base key HKEY_DYN_DATA.

"The DynData registry key only works on Win9x, which is no longer supported by the CLR.  On NT-based operating systems, use the PerformanceData registry key instead."

LocalMachine : Contains the configuration data for the local machine. This field reads the Windows registry base key HKEY_LOCAL_MACHINE.

PerformanceData :  Contains performance information for software components. This field reads the Windows registry base key HKEY_PERFORMANCE_DATA.

Users :  Contains information about the default user configuration. This field reads the Windows registry base key HKEY_USERS.

1. Open the registry Key.

*Suppose we need to open the key and it is under the HKEY_LOCAL_USER

            RegistryKey rk = Registry.CurrentUser;

            string subKey = "tmentor";

            RegistryKey sk = rk.OpenSubKey(subKey);

            if (sk == null)

            {

                // key is not available

                //TODO Code

            }

            else

            {

                // key is available and open

                //TODO Code

            }

* Add a new Key

            RegistryKey rk = Registry.CurrentUser;

            string subKey = "tmentor";

            RegistryKey sk = rk.OpenSubKey(subKey);

            if (sk == null)

            {

                sk.CreateSubKey("tmentor");

            }

           

* Add/Update a new key value

            RegistryKey rk = Registry.CurrentUser;

            string subKey = "tmentor";

            RegistryKey sk = rk.OpenSubKey(subKey, true);

            if (sk != null)          

            {

                sk.SetValue("IsRegistryAdded", "1");

            }