The Read method and the 64-bit overloads of the Increment, Decrement, and Add methods are truly atomic only on systems where a System.IntPtr is 64 bits long. On other systems, these methods are atomic with respect to each other, but not with respect to other means of accessing the data. Thus, to be thread safe on 32-bit systems, any access to a 64-bit value must be made through the members of the Interlocked class.
Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.