What you really need is a program that does housekeeping for you and helps keep your computer clean and free from any junk that can accumulate. A very popular and free program for this is CCleaner. All of the default settings are configured so it can be used immediately without any fuss:
http://www.ccleaner.com/
If you would rather just do it manually instructions below ar for IE and Opera. If you use FireFox or another alternative a Google search for
Clean temporary files firefox (your browser name) should work fine:
IE
Open an IE browser page■
Click on "Tools" at the top right of the page.■
Clik on "Internet Options"■
Under the "General" tab click on "Delete" for browsing history.■
Here you are given the options of exactly which you want to delete. It will probably be enough to do your Temporary Internet Files and Cookies. For me I just use the bottom option to "Delete All"
Opera
Open an Opera browser page■
Click on "Tools" at the top of the page■
Click on "Delete Private Data"■
The default settings here are all configured to delete browsing history and cookies.
By clearing internet temporary files and cookies you will need to login into any sites that need passwords and all URLs will need to be re-entered in full.