How to remove these hacks or viruses?

[wuguiboi]

Hi, recently i came across a few notices on asking me for permission to access my mouse,DNS, keyboards, speaker when i accept buddy request from facebook and hotmail messenger. Due to some circumstances in my real life,i do believe that the hackers did use this kind of method to track my computer and also these hackers are my schoolmates. I ask them about it but they say they did not. Here's one example to why i believe that hey are tracking, i was listening to music and they produce beats which asscioates to the part that i'm listeining to right now. However i reformatted my computer recently but i received another messages sent from a forum which i didn't subscribed and the circumstances that i have said out happens again after i click the messages. If this hacks are true, then anyone who are using hotmail can be infected by this. Please help me in removing this hack and give some tips on how to prevent this. Thanks.