This MSVCR100.dll is missing when WAMP server install problem mostly happen when you install new ‘Operating system’.
That MSVCR100.dll file is one part of Microsoft Visual C++. IF this component is missing means, ‘Apache Server’ won’t run. So, download following exe file and just install that. It’s enough for MSVCR100.dll is missing when WAMP server install problem.

For Windows 32 bit OS:

Microsoft Visual C++ 2008 SP1 Redistributable Package (x86)

Microsoft Visual C++ 2010 SP1 Redistributable Package (x86)

Here just select your Language and click ‘Download’ Button. You will get ‘vcredist_x86.exe’ file. Just Download that file and install as usual( double click ).

For Windows 64 bit OS:

Visual C++ Redistributable for Visual Studio 2012 Update 4

Microsoft Visual C++ 2008 Redistributable Package (x64)

Microsoft Visual C++ 2010 SP1 Redistributable Package (x64)

Here just select your Language and click ‘Download’ Button. You will get ‘vcredist_x64.exe’ file. Just Download that file and install as usual( double click ).

Notes:
1) Make sure you have the latest service pack and critical updates for the version of Windows that you are running. To find recent security updates, visit Windows Update.
2)Supported Operating System: Windows 7, Windows Server 2003, Windows Server 2008, Windows Server 2008 R2, Windows Vista, Windows XP
3)Make sure you have the latest version of packages of these Microsoft C++ Redistributable runtime libraries. We recommended 2008 Packages for over-all.
4)This the solution for error: Aestan Tray Menu has stopped working and Exception in module wampmanager.exe at 000F15A0