OS means operating system (Windows XP; Vista: W7: or whatever)
Yes , you need Flash to be working properly so as to play Mamya's music threads. Consequently, it's the area of Flash that appears to need attention.
Forget for the moment any downloading and running of uninstall tool. However, click open Control Panel > Programmes and features > Adobe Flash Player Plugin > Disable....... Then download from the following site :-
http://get.adobe.com/flashplayer/
Make sure that you untick the McAfee box before clicking to download the Flash Player. After downloading it will be necessary to run the file which you should find in your 'Downloads' folder.
Hopefully that should put matters right.
Al.