The following is the way I had to go to get rid of a peresistant hi-jacker
Go into start/search and search for whatever you are getting delete all instances you find.
Then go into the registry by typing rededit at start/run.
Once in the registry go to edit/find and search for whatever you are getting, continue to search by clicking 'find next' until you have searched and removed all instances of whatever you are getting from the registry.
Go into start/run and type msconfig 'ok' click the startup tab and untick any instance of reg32 and reg33 disable system restore and reboot.