Hi,

1. Do you have an Old Firefox data folder on your desktop?
2. Are there any folders in the Firefox Profiles folder? You can access it by going to about:support, clicking Open Folder next to Profile Folder and going one level up.

I got so frustrated with not being able to reinstall Firefox, that I deleted all the profiles after copying them to an external hard drive. I read your solution and copied the file ending in.test from the Old Firefox data folder on my desktop to the AppData/Roaming/Mozilla/Firefox/ profile. Then I copied the biggest file ending in .default from the backed up Local profiles to the AppData/Local/Mozilla/Firefox/ profile. It doesn't matter if I delete or keep the Old Firefox data folder on my desktop, I still get the Profile Missing error message. What can I do, so my laptop would appear as if it had been powered up straight out of the box and never had Firefox initially installed?

I got so frustrated with not being able to reinstall Firefox, that I deleted all the profiles after copying them to an external hard drive. I read your solution and copied the file ending in.test from the Old Firefox data folder on my desktop to the AppData/Roaming/Mozilla/Firefox/ profile. Then I copied the biggest file ending in .default from the backed up Local profiles to the AppData/Local/Mozilla/Firefox/ profile. It doesn't matter if I delete or keep the Old Firefox data folder on my desktop, I still get the Profile Missing error message. What can I do, so my laptop would appear as if it had been powered up straight out of the box and never had Firefox initially installed?

Hi Richard, since you are clearly having a different issue, please ask a new question instead of posting here.

Just a heads-up, from you description here I don't fully understand what the issue is. What was preventing you from reinstalling Firefox? Why did you tried copying files in the first place? If you just want to get a clean Firefox install (without your data), please see Uninstall Firefox from your computer (and then just install the browser again normally).