download CC cleaner, it's free, run and clean up your history ect, go to the registry checker and scan for issues, when it asks do you want to back up before changes always backup. Go to the uninstall section and uninstall any programmes you don't use anymore, rerun the cleaner again. down load malawarebytes, its free again, and run a full scan, can take hours but it will check for any malware which can slow down your pc, check that your antivirus checker is upto date, if not update or if it costs download a freebe like Avast or AVG, if you bank online the banks often give you a years free ant