Also im pretty sure remote desktop is off by default. I could be wrong but the last versions (3) of windows 7 ive had installed have all had them off. Chances are if someone did remote desktop your PC then they knew a username/password combination that you lent them, and they turned remote desktop on (or it was on by default, but im pretty sure its off by default). But since your the only one with acess to your PC then i guess it was on by default. Then all someone would need is an IP adress ( not hard ) and a username /password.