It seems blizz did it again, because they never learn :)

MSVCR120.dll file got missing in Azeroth
[NEW] Path 1.27 - Missing MSVCR120.dll file error

Fix by r.2.d.2_PL

Warcraft 3 uses microsoft Visual C++ 8.0 runtime libraries. If the libraries are not installed in the system - w3 gives warning about the system misconfiguration.

You can download microsoft libraries from here. Don't worry - digitally signed by microsoft. Taken from VC5 package and legal to distribute freely. After the installation Warcraft3 will run normally.

Download here

Step 2: If it didn't worked **

** you should do it after you tried previous method but it didn't worked

If installation of previous file didn't worked and WC3 still can't be run you need new version of microsoft installer (download page - directly from microsoft). Select your OS language from list, then go bottom and you'll find something like WindowsInstaller-KB893803-v2-x86.exe
Download this, install and then run the fix by r2.d.2_PL again.

Related:

Having problems running the path installer (but the game runs OK)?
I have fix for that too... warcraft 3 patching program fix