go to start run---regedit
on right hand side look for Hkey_loacl_machine
-click on plus sign before HKLM
look for software\microsoft\windows\current version\run
do not click on plus sign next to run but click on word run
on right hand side the first thing would be default
other than default, right click on rest of them one by one and delete
Follow the same path for Hkey_current_user and do same