In FF
Tools->Clear Private Data. Check all the boxes and click Clean Private Data Now.
In IE
Tools->Internet Options->General tab->Under Browsing history, click delete->Select all and click on Delete.
On ( IE) go up to tools click on it.Then u will see internet prop ties click on it.Then u will see internet options.From here u will see browsing history. Click on delete this will bring up cookies, internet temp files .pass words data Information.Click on delete then click on delete all.This will delete all the above make u click on save after everything has been deleted. That's it.