Windows 10 reached EOS (end of support) on October 14, 2025. For more information, see this article.

Sykje yn Support

Mij stipescams. Wy sille jo nea freegje in telefoannûmer te beljen, der in sms nei ta te stjoeren of persoanlike gegevens te dielen. Meld fertochte aktiviteit mei de opsje ‘Misbrûk melde’.

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Dizze konversaasje is argivearre. Stel in nije fraach as jo help nedich hawwe.

where is userContent.css?

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Hi, I want to use dark background color theme in the Mozilla Firefox PDF viewer, read here https://support.mozilla.org/en-US/questions/1434510 but cannot find "userContent.css". My question is where can I find this file on a Windows 7 or Windows 10 installation?

Hi, I want to use dark background color theme in the Mozilla Firefox PDF viewer, read here https://support.mozilla.org/en-US/questions/1434510 but cannot find "userContent.css". My question is where can I find this file on a Windows 7 or Windows 10 installation?

Alle antwurden (1)

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You have to create it.

Go to about:support. Look down the blue block on the left of the screen that will open until you come to Profile Directory. Click the Open Directory button next to it. This will open your Profile Directory in Windows Explorer.

Make a directory/folder in that called chrome, all lower case. In that, ie the directory you've just created, put your userContent.css file.

If you haven't already you need to go to about:config and set toolkit.legacyUserProfileCustomizations.stylesheets to true for your changes to work.