Unisnstalling McAfee

I have Dell computer,dimension 2350 I did an uninstalling McAfee antivirus program,was really hard to remove it but anyway I did .Now when I start the computer  they are two notices the first said reinstall virus scan online and the second is restart  computer in safe mode active shield is missing .Now I have tried to remove but I can't .I  have checked Registry editor there is a file McAfee.com but doesn.t go from there,i used search for files McAfee but there is no files said also i used start/run /msconfig,I see there are three files McAfee but when I restart the computer they are still there.Please those noticies are annoying me.How can I get ride of McAfee files?