When CTRL + F5 is not enough: here you can find useful tips to remove cookies.
Internet explorer 10 en 11
1. Click 'tools icon' (blue or grey the Gear Icon), at the top right of the browser
2. Click on 'Safety'
3. Click on 'Delete browsing history....'
4. Select Temporary Internet Files and Cookies
5. Click Delete
Internet Explorer 8 en 9
1. Click on Security or Extra (Tools)
2. Click on 'Delete browsing history'
3. Choose the desired functions
Firefox
1. Click the menu button , then Library, followed by History.
2. Click Clear Recent History....
3. Set Time range to clear to Everything.
4. Click on the arrow next to Details to expand the list of history items.
5. Select Cookies and make sure that other items you want to keep are not selected.
Chrome
1. On your computer, open Chrome.
2. At the top right, click More.
3. Click More tools Clear browsing data.
4. At the top, choose a time range. To delete everything, select All time.
5. Next to "Cookies and other site data" and "Cached images and files," check the boxes.
6. Click Clear data.