The startup time is greatly affected by all the applications you have loading and launching automatically on startup. Go to Run or in Search for Win 7 or Vista (if you’re running 8 or later see instructions below) and type in msconfig hit enter to launch it. In the System Configuration window that pops up go to the Startup tab and uncheck the applications that you don’t need launching right away such as messengers, any 3ed party stuff that likes to run in the background. DON’T TOUCH THE INTEL, MICROSOFT, AND LAPTOP MANUFACTURER ITEMS, unless you know what they do and you know they are not needed by the system. Click Apply > OK> and restart. When your PC loads back up you might get a prompt that system settings were changed, check the box and click ok. If you are running Windows 8 or later you can get to the startup items from Task Manager. Right click on the bottom Windows bar > Start Task Manager > Startup.
Take a look at the amount of files you have on your desktop. Explorer>Users>(your username)>Desktop. Right click on Desktop folder and see the size of the folder. If there’s more then 1GB if will dramatically effect the speed of your machine. Move large files to Documents and create shortcut to the file on the desktop if you need easy access to them. Also take a look at the amount of file icons that are sitting there, if most of your desktop space is taken up by them – group them into folder.
You should also go through the list of applications that you have installed (Control Panel> Programs and Features) and uninstall everything you no longer use, especially any toolbars that got downloaded along the way.
Clearing temp files for windows and browsers will all generally speed up you machine.