What am i supposed to do with rar files?

To open those files, you need a program like :
7z
WinRAR

Is there any password to extract the files?

There is no password for the files shared here, unless there is a mention of one.

Trouble to install/run the game?

Check the tutorials section, here:
Tutorials list

If it doesn't help you, please create a topic.

My antivirus detects a threat inside a file

Some games need a crack to run properly.
You have to disable or make an exception inside your antivirus program, there is no alternative.

Is the game fully working ?

Every games here are tested and are fully functionnals, if it's not the case, there will be a mention.
If you have a problem, please create a topic.

I have a message error about missing dll when i run a game, what should i do?

Please install every updates of Visual C++, DirectX or .netFramework.
Check this link :
Useful tools

Install both versions of Visual C++ (x64 and x86).