Sorry, but as far as I know, Sync cannot erase data from your PC unless it is erased from another device connected to the same account. In other words, if you do NOT change your password, and the thief starts your computer, guesses your password, and runs Firefox, when Firefox syncs, it may discover that it's not supposed to have any bookmarks and erase the local copy. I've never tested that, of course.

But bear in mind that Firefox keeps several bookmark backups, so the thief would be able to dig around and find them if they really wanted them. There's not really a way to remotely "wipe" your Firefox data completely using any built-in feature.

For future reference, the only way to prevent someone from recovering data from a stolen computer is "full disk encryption" (FDE). Otherwise, they can pull out your drive, attach it to another system, and just copy everything right off.

hi jscher2000 many thanks for your reply. So, i reinstalled firefox on another pc, changed password TWICE (using same account details) and then turned sync OFF. It removed all the bookmarks from firefox on my phone so i assumed it would do the same on another Pc also.

If it is the main PC it should stay I would think. Sorry I do not use it. Hope so for you.

Pkshadow said

If it is the main PC . . . .

There is no 'main' in sync. All selected data is shared between all devices/profiles on the sync. A change on one is shared with all.

Thank you to everyone for their replies. As a matter of interest only, if Firefox is deleted from any PC or a refresh is done on that PC all data would then be lost??

Only on that PC. Have you notified your police?

pleasehelpmeee said

As a matter of interest only, if Firefox is deleted from any PC or a refresh is done on that PC all data would then be lost??

Firefox has separate program folders and data folders. A simple uninstall (using Firefox's built-in uninstaller) does not remove the data folder, it would need to be deleted by hand. For more information on the location of the folder, see: Profiles - Where Firefox stores your bookmarks, passwords and other user data.

Regarding a Refresh: A Firefox refresh does not delete your profile folder, it moves it to the desktop in a folder named Old Firefox Data. A Windows 10 refresh presents options for whether to leave data in place, store it in a temporary folder (C:\Windows.old), or delete it. Other versions of Windows may vary.

Thank you jscher2000 for clarification. So if you choose refresh and choose to remove all programs etc I assume the data will be gone completely with no option to revert anything back other than reinstalling any programs again. Thank you once again for your help.

pleasehelpmeee said

So if you choose refresh and choose to remove all programs etc I assume the data will be gone completely with no option to revert anything back other than reinstalling any programs again.

I've never done that myself, but based on people reporting that their data was gone, I think it would remove it.