Try starting Firefox in Safe Mode by holding the Shift key when double-clicking the icon.

If that helps, try disabling hardware graphics acceleration in case there is a graphics driver incompatibility.

You usually need to restart Firefox in order for this to take effect, so save all work first (e.g., mail you are composing, online documents you're editing, etc.).

orange Firefox button (or Tools menu) > Options > Advanced

On the "General" mini-tab, uncheck the box for "Use hardware acceleration when available"

If you restart Firefox, is the issue resolved (or at least improved)?

Thanks, starting Firefox in Safe Mode works, however, do not have the option to disable graphics acceleration. The change button is grayed out. If you try and start Firefox other then in safe mode, same problem. At least it works that way.

Can you get to the Options dialog in normal mode? If the menu is unreadable, the keyboard combination for Tools > Options would be one press on each of the following keys in sequence:

Alt t o

If the dialog is blacked out, too, then we'd have to edit a file on disk to disable the preference.