Try to disable hardware acceleration.

• Tools > Options > Advanced > General > Browsing: "Use hardware acceleration when available"

If disabling hardware acceleration works then check if there is an update available for your graphics display driver.

Start Firefox in Diagnose Firefox issues using Troubleshoot Mode to check if one of the extensions or if hardware acceleration is causing the problem (switch to the DEFAULT theme: Firefox (Tools) > Add-ons > Appearance/Themes).

• Don't make any changes on the Safe mode start window.
• https://support.mozilla.com/kb/Safe+Mode

Hello! Thanks for the quick response but unfortunately none of the things that you suggested worked... Hardware acceleration is already disabled (it causes even more problems, flickering etc.) and the problem persists even when starting in Safe mode.

Create a new profile as a test to check if your current profile is causing the problems.

See "Basic Troubleshooting: Make a new profile":

• https://support.mozilla.com/kb/Basic+Troubleshooting#w_8-make-a-new-profile

There may be extensions and plugins installed by default in a new profile, so check that in "Tools > Add-ons > Extensions & Plugins" in case there are still problems.

If that new profile works then you can transfer some files from the old profile to that new profile, but be careful not to copy corrupted files.

See:

• http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox

This is getting frustrating (more for you than for me I'm sure)... Thanks for the help but unfortunately the problem persists.. I opened Firefox under a new profile, disabled all Plugins and Extensions, restarted Firefox but it did no good... Same problem still persists.

Are you using a non-default Windows theme or made changes yourself?

Control Panel > Personalization > Theme & Window Color and Appearance