@gollum,
Method 1: Delete cookies through the setting named "Delete cookies or temporary files".
Step 1: Press Windows Key+F to open the Search bar, enter cookies in the empty box, select Settings and click Delete cookies or temporary files on the result page.
Step 2: As the Internet Properties window opens, check the box before Delete browsing history on exit and tap Delete button.
Step 3: Check the box before Cookies and website data and click Delete to confirm deleting cookies.
Method 2: Delete cookies through deleting browsing history.
Step 1: Open IE, click Tools on the Menu Bar and select Delete browsing history.
Step 2: In the Delete Browsing History window, choose Cookies and website data and click Delete.