WAMP shows error 'MSVCR100.dll' is missing when install

The MSVCR100.dll file is part of the Microsoft Visual C++, redistributables. You can install them and see if this solves your problem. After you install the above check if your wamp installation is correctly setup. This article on the WampServer forums shows all the Microsoft Visual C++ runtime libraries you need to have installed on your system for each version of WampServer. To quote: For Windows 32 : Be sure that you have installed the Visual C++ 2010 SP1 Redistributable Package x86 : VC10 SP1 vcredist_x86.exe http://www.microsoft.com/download/en/details.aspx?id=8328 For Windows 64 : Be sure that you have installed the Visual C++ 2010 SP1 Redistributable Package x64 : VC10 SP1 vcredist_x64.exe http://www.microsoft.com/download/en/details.aspx?id=13523 Apache will not run without this component In fact if you are running the 64bit Windows it is a good idea to install all the 32bit libraries as well as the 64bit ones. After all 64bit windows runs 64 and 32 bit code. You will probably find you need at least one of the 32bit runtimes for some app/utility you will install at some point. UPDATE If you are running WAMPServer 2.5 you also need the VC11 redist. Visual C++ Redistributable for Visual Studio 2012 29.08.2014 with WAMP 2.5 I agree that VC11 is needed and it is not a bad idea to have previous distributions installed. It will be needed by other application. I am not sure if you need bit 32 version http://www.microsoft.com/en-us/download/confirmation.aspx?id=30679