how do I clear scam widows off of my computer

Hi Does clearing your browsing history help?

https://support.mozilla.org/en-US/kb/push-notifications-firefox#w_how-do-i-revoke-the-notifications-permission-for-a-specific-site Are these as small popups on bottom right corner of Firefox window?. If so then these may just be web push notifications from sites you have allowed to send you notifications. Instead of useful information some may send you junk, spam fake virus/trojan alerts etc. You can revoke the sites from sending you notifications as shown in above kb article link Also these are not alerts from Mozilla nor the Firefox web browser as they do not do such alerts.