If this is an issue, consider uninstalling Google Chrome from your computer.

Clearing your cache and cookies will most likely not repair this issue.
If you still want to try clearing the cache and cookies, you can use another program (ie. CCleaner).
What is happening when you try to clear the cache?

If you still cannot get Google Chrome to stop becoming the default internet browser, please manually set Firefox as the default on your Windows 7 system. ^{(More Details)}

Please report back soon.
I hope that this will solve your issue.

You will see varying instructions on how to clear cookies, because Firefox's interface can be customized in different ways. For example, if you do not have a large orange button in the upper left corner that says Firefox, then you may have the classic menu bar. On the menu bar, you can use the Tools menu to get to the Options dialog, or the History menu to use Clear Recent History.

To clear the cookies just for one site, here's another way. While viewing a page on the site, try either:

• right-click and choose View Page Info > Security > "View Cookies"
• Alt+t (open the classic Tools menu) > Page Info > Security > "View Cookies"

In the dialog that opens, you can remove the site's cookies individually.

(Note that if you are in the middle of anything on the site, you should save your work first because deleting the cookie will log you out.)

Make sure that you do not run Firefox in full screen mode (press F11 or Fn + F11 to toggle; Mac: Command+Shift+F).

• https://support.mozilla.org/kb/how-to-use-full-screen

If you are in full screen mode then hover the mouse to the top of the screen to make the Navigation Toolbar and Tab bar appear.
Click the Maximize button (top right corner of the Navigation Toolbar) to leave full screen mode or right-click empty space on a toolbar and choose "Exit Full Screen Mode" or press the F11 key.

Make sure that toolbars like the "Navigation Toolbar" and the "Bookmarks Toolbar" are visible.

• Firefox menu button > Options
• View > Toolbars (press F10 to display the menu bar)
• Right-click empty toolbar area

See also:

• https://support.mozilla.org/kb/how-do-i-get-firefox-button
• https://support.mozilla.org/kb/Menu+bar+is+missing
• https://support.mozilla.org/kb/How+to+customize+the+toolbar