Go to Start, Run and type msconfig and press enter. on the next window select Startup. You will see a list of all programmes that start when you boot up. Untick the ones you do not want to start and reboot. DO NOT UNTICK ScanRegistry, SystemTray, LoadPowerProfile or any Anti Virus programme you have or any Firewall programme you may have. If you find something doesn't work afterwards go back into msconfig and put the tick back in again and reboot.
Click Start--> Startup. You can delete some of the items from this list, but it might be dangerous. You need: right click on a proggramm you don't want to run at startup--> properties-->Find Target. You'll see the folder with a lots of files. Unintallation file can be called "uninstall" or "unwise". Otherwise click Start--> Control Panel--> Add/remove proggrams--> You can remove now unwantes programms, but be carefull some of the programs can be used by System.