Unity wont launch

So last night I finally decided to start learning to use unity, I downloaded unity 4 free and started following some beginner tutorials. However, this evening when I tried to launch unity, it failed to do so and returned the following error;
/*
Unable to load mono library from “C:/Program Files (x86)/Unity/Editor/Data/Mono/EmbedRuntime/mono.dll” (error = 126).
*/
I haven’t made any changes since the last time I launched, so I am confused as to what is causing it. Advice is much appreciated!

Hi,

I had the same problem u have to re install the C:/Program Files (x86)/Unity/* folder, because more files are missing, not just the file in the error.

Keeping an already installed unity in a zip can also saves time to fix this problem.