If you forgot your password for a .rar archive then i have solution for you .

Thing you need is

After downloading go open the rar and instal it .
Now open the folder and run password recovery tool,a window will appear
After this open the rar file of which you want password and leave the software it will take few minutes
Like this one.










 
Then a window will appear which will give you password of your rar file.
like this. Cheers