WAMP won't turn green. And the VCRUNTIME140.dll error

As Oriol said, you need the following redistributables before installing WAMP.

From the readme.txt

BEFORE proceeding with the installation of Wampserver, you must ensure that certain elements are installed on your system, otherwise Wampserver will absolutely not run, and in addition, the installation will be faulty and you need to remove Wampserver BEFORE installing the elements that were missing.

Make sure you are "up to date" in the redistributable packages VC9, VC10, VC11, VC13 and VC14 Even if you think you are up to date, install each package as administrator and if message "Already installed", validate Repair.

The following packages (VC9, VC10, VC11) are imperatively required to Wampserver 2.4, 2.5 and 3.0, even if you use only Apache and PHP versions VC11 and VC14 is required for PHP 7 and Apache 2.4.17

• VC9 Packages (Visual C++ 2008 SP1)
  https://www.microsoft.com/en-us/download/details.aspx?id=5582
  https://www.microsoft.com/en-us/download/details.aspx?id=2092

• VC10 Packages (Visual C++ 2010 SP1)
  https://www.microsoft.com/en-us/download/details.aspx?id=8328
  https://www.microsoft.com/en-us/download/details.aspx?id=13523

• VC11 Packages (Visual C++ 2012 Update 4)The two files VSU4\vcredist_x86.exe and VSU4\vcredist_x64.exe to be download are on the same page:http://www.microsoft.com/en-us/download/details.aspx?id=30679

• VC13 Packages[/b] (Visual C++ 2013)The two files VSU4\vcredist_x86.exe and VSU4\vcredist_x64.exe

• VC14 Packages (Visual C++ 2015)The two files vcredist_x86.exe and vcredist_x64.exe to be download are on the same page:https://www.microsoft.com/en-us/download/details.aspx?id=52685

• VC Packages x64 (Visual C++ 2017)

https://support.microsoft.com/en-us/help/2977003/the-latest-supported-visual-c-downloads

Quite simply:

1. Uninstall wampserver
2. Install Visual C++ Redistributable for Visual Studio 2015
3. Install wampserver

VCRUNTIME140.dll error

This error means you don't have required Visual C++ packages installed in your computer.If you have installed wampserver then firstly uninstall wampserver.

Download the VC packages

Download all these VC packages and install all of them. You should install both 64 bit and 32 bit version.

-- VC9 Packages (Visual C++ 2008 SP1)--
http://www.microsoft.com/en-us/download/details.aspx?id=5582
http://www.microsoft.com/en-us/download/details.aspx?id=2092

-- VC10 Packages (Visual C++ 2010 SP1)--
http://www.microsoft.com/en-us/download/details.aspx?id=8328
http://www.microsoft.com/en-us/download/details.aspx?id=13523

-- VC11 Packages (Visual C++ 2012 Update 4)--
The two files VSU4\vcredist_x86.exe and VSU4\vcredist_x64.exe to be download are on the same page
http://www.microsoft.com/en-us/download/details.aspx?id=30679

-- VC13 Packages] (Visual C++ 2013)--
The two files VSU4\vcredist_x86.exe and VSU4\vcredist_x64.exe to be download are on the same page
https://www.microsoft.com/en-us/download/details.aspx?id=40784

-- VC14 Packages (Visual C++ 2015)--
The two files vcredist_x86.exe and vcredist_x64.exe to be download are on the same page
http://www.microsoft.com/en-us/download/details.aspx?id=48145

install packages with admin priviliges
Right click->Run as Administrator

install wampserver again
After you installed both 64bits and 32 bits version of VC packages then install wampserver again.