There are two types of codes available in C#.NET for checking the status of CAPS Lock and NUM Lock. a. Unmanaged Code : The code written in conventional languages like C, C++, VC++ etc. This kind of code can be called in the Managed Environment like .NET, JRE etc. [ DllImport ( "user32.dll" , CharSet = CharSet .Auto, ExactSpelling = true , CallingConvention = CallingConvention .Winapi)] public static extern short GetKeyState( int keyCode); bool CapsLock = ((( ushort )GetKeyState(0x14)) & 0xffff) != 0; bool NumLock = ((( ushort )GetKeyState(0x90)) & 0xffff) != 0; bool ScrollLock = ((( ushort )GetKeyState(0x91)) & 0xffff) != 0; MessageBox .Show( "Caps Lock is on: " + CapsLock.ToString()); MessageBox .Show( "Num Lock is on: " + NumLock.ToString()); MessageBox .Show( "Scroll Lock is on: " + ScrollLock.ToString()); b. Managed Code: Code which is managed by the Runtime environment. This type of code is basically a wr