computer won't go to a bookmarked site ?

First, a browser, like Firefox or Chrome, has very little to do with a computer's OS (Windows 10), unless you have a virus.

DFord wrote:
Download and install MalwareBytes on your damaged machine. Then run a scan with it. MalwareBytes has a free version that can be run manually where the paid version runs full time in the background to protect you. It will find and remove the BS on your PC.

MalwareBytes Download Page

Some anti-virus software may prevent you from going to a website because the think it is "dangerous"/contains a virus.

The other tool, I live by is CCleaner. Not only does is "clean up" various unneeded files on your hard drive it also cleans up the registry. I have been using the FREE version of CCleaner for years on multiple computer with no issues. (Don't install any of the "optional" software.)

If you can download those two pieces of software you know your Internet connection is working.

If those tool do not solve you problem, you need to clear your Firefox cookies and cache (CCleaner will do this for you).

If that dose not solve your problem, see if you can manually type the URL into the address bar and it works. If not the address may be wrong or has changed. Using a different PC, verify the address.

The only way to truly "reset" Firefox is to uninstall it (CCleaner Tools, left column) and tell it not to remember any settings. Reboot, download Firefox and re-install.

Or try Chrome.

Download and install MalwareBytes on your damaged machine. Then run a scan with it. MalwareBytes has a free version that can be run manually where the paid version runs full time in the background to protect you. It will find and remove the BS on your PC.

MalwareBytes Download Page

I have that problem when the bookmarked site moves.. Or just plain goes dark.

Now for one page (Pi-star.local) I just ask the router where it went and type in the new number and it works. but that's a .local site

(I'm no computer expert so give my advice the attention it deserves)

If all else fails and before you reset your computer, your Firefox profile might be corrupted. Save your bookmarks - Bookmarks/Show All Bookmarks/Backup. Type "about:profiles" in your address bar. When the page loads you can create a new profile. You can import your exported bookmarks into the new profile. It's good to do this every year or so anyway to get rid of all the crud that builds up, similar to your computer registry.

Don't get carried away here.

Find the actual URL in your bookmark list.
Type that URL into the address line manually.

The site might not exist anymore.....or someone else might own the URL now.

sounds like the content the memorized URL is pointing to has changed. this happens every now and then