type system configuration into search box the click start up tab , do you see anything you dont recognise , if so untick it.
go to add/remove and look for any software items you dont recognise and uninstall them.
download the free version of antimal warebytes , when you run a scan , if it finds anything the program will quarantine it , after a restart go to the quarantine tab and delete what it finds... VERY IMPORTANT ..... spywear nasties etc can be made up of several segments and it is not always possible to find and delete everything on the first scans. you MUST do repeat scans until nothing is found.