Hello well gota start by saying am new to the Mac world, so i hope this explain wat am about to ask ... first am using an iMac OS X 10.6.8 - and its a second hand, well am not sure if you could consider it a second hand, but in a perfect condition, considering the fact i got it from my " FRIEND " for free, or as an exchange for some hook ups ( leaving in it to that ) well the problem in short is that i am trying to figure out if someone else got access to this computer over the net, considering that my " FRIEND " had this computer under his hands and he could've installed any of the spy software or even hacked the system in a way that he could access it over the net discreetly for further future use, and am sure he got his good background in programing, several operating systems. so in short what got me thinking all of this is the following .... - Slow internet connection althou am using a really fast internet connection, fiber optic tech. and also the net is only slow when am using this iMac - missing Emails, and files, on my emails and on my iMac - weird sound from the iMac like its processing something when am not even touching it. - i have to reestablish my wireless connection from time to time like am loosing to another machine that is connected to my internet network. in another words i had my reason to take my iMac to a certified Apple service center in my town to fully format and upgrade my OS ( i think it was 10.2.7 not sure). i also explained to them my problems and my doubts and they assured me it wont be a problem. Here where i want you guys to help me out doing it my self, or reassuring myself PLEASE ( my family also use this iMac ) - How could i make sure that no other computer is connected to this iMac thru a port or Desktop control Utility - or even spyware/keylogger Also whats the best way to restrict access to this Computer i just wanted to be spesific about my info and problem so you guys could help me out as much as possible ..... R.I.P. S.J.