Hello, sorry for the inconvenience in your troubles with Firefox. Can you describe what window was prompted for your download? There's a potential threat of a random pop-up being a fake download. Let us know, and we'll help you to our best ability.

Once in a while when I was on the internet (Firefox) a new tab would pop up with "download the latest version of firefox". A while back I almost fell for it. Then I looked up if that 'Patch' was a hoax and said it was so I never downloaded it.

But again I kept seeing a newer version was out there so went on to Firefox's website and clicked on the Download. Unfortunately you have advertisers who want you to download maps or something and I accidentially clicked on that (thanks Firefox) and had to start it over. But I did the Firefox download from Firefox's website.

So this error code relates to... 0xc000000f – An error occurred while attempting to read the boot configuration data

Have you tried rebooting your PC. Upon doing so, make sure Windows detects the problem. And if you receive another error code upon logging back onto your computer. Could you screen shot and upload that photo in a comment? (Ctrl + PrtScn) to Screenshot (Ctrl + V) Paste into Paint program Upload image after saving the image.

Edit: Someone is working on this Support Thread, didn't see until after. He'll be able to assist your furthermore!

Best Wishes!

Does the screen appear only when you start Firefox and otherwise everything is normal? If this runs outside of Firefox, please treat it as a malware emergency and see this article: Troubleshoot Firefox issues caused by malware.

If this only appears when you start Firefox, I think there are three possibilities:

(1) It's a tech support scam page. Some ad networks allow these sites and they put up fairly convincing screens indicating there's a problem and you need to call them (and pay) to fix it. Sometimes pressing the Esc key several times in rapid succession will break the cycle of the ad script and let you exit the site normally. That's best because crashing out of Firefox usually leads Firefox to try to restore the same bad page at the next startup. More tips on this if it turns out to be relevant.

(2) Your Firefox has become infected with a bad extension. I'll give you a long note on that in a minute.

(3) Your Firefox shortcut -- the one you use to start Firefox -- has been hijacked to a page that shows a tech support scam. One way to check for this is to start Firefox in a different way, such as using a Windows favorite (if Firefox is your default browser) or pasting the command line into the Windows Run dialog or into the Windows 10 search box (and pressing Enter to run it):

firefox.exe -url "about:home"

Here's my suggested procedure for tracking down and cleaning up bad add-ons and other hijackers. I know it seems long, but it's really not that bad.

(1) Open the Windows Control Panel, Uninstall a Program.

After the list loads, click the "Installed on" column heading to group the infections, I mean, additions, by date. This can help in smoking out undisclosed bundle items that snuck in with some software you agreed to install. Be suspicious of everything you do not recognize/remember, as malware often uses important or innocent sounding names to discourage you from removing it.

Take out as much trash as possible here. If you're not sure, feel free to post program names or a screenshot of the list.

(2) Open Firefox's Add-ons page using either:

• Ctrl+Shift+a (Mac: Command+Shift+a)
• "3-bar" menu button (or Tools menu) > Add-ons
• in the Windows "Run" dialog, type or paste this command line and press Enter to load it:
  firefox.exe "about:addons"

In the left column, click Extensions. Then, if in doubt, disable (or Remove, if possible) unrecognized and unwanted extensions; the troublemaker might not be obvious from its name. All Mozilla-installed extensions are hidden from this page, so whatever you see here is your choice and your responsibility to enable, disable, or remove.

Often a link will appear above at least one disabled extension to restart Firefox. You can complete your work on the tab and click one of the links as the last step.

Any improvement?

(3) You can search for remaining issues with the scanning/cleaning tools listed in our support article:Troubleshoot Firefox issues caused by malware. These on-demand scanners are free and take considerable time to run. If they finish quickly and especially if they require payment, you may have a serious infection. I suggest the specialized forums listed in the article in that case.

(4) Then finally if needed:

• Restore your preferred home page: How to set the home page
• Restore your preferred default search engine: Change your default search settings in Firefox

If your home page works in new Windows (Ctrl+n) but you get a different page at startup:

Investigate Your Shortcut

The Firefox icon can be set up to launch specific pages at startup (or more specifically, when you use the icon). To check whether that is set:

First, open the shortcut as follows:

• Desktop shortcut: right-click the icon, choose Properties
• Pinned taskbar icon: right-click the icon, right-click Mozilla Firefox, choose Properties

Windows normally will select the Shortcut tab. If not, go ahead and click the Shortcut tab.

You'll see the Target highlighted. On 64-bit Windows, that usually is no more and no less than the following:

"C:\Program Files (x86)\Mozilla Firefox\firefox.exe"

If anything follows after that, try clearing it out.

After OK'ing the Properties dialog, you can test right away to confirm that Firefox now launches only your home page. Either:

• double-click desktop shortcut
• right-click pinned taskbar icon, click Mozilla Firefox

Success?

Yes I tried rebooting but now the recovery screen is the only thing that appears. I haven't even gotten to the log in screen of Windows 10 yet.

I can't get a picture of it to attach to this response. I'll keep trying on that. Any other suggestions?

The entire blue screen states the following:

Recovery You PC/Device needs to be repaired A required device isn't connected or can't be accessed. Error Code: 0xc000000f You'll need to use recovery tools. If you don't have any installation media contact your PC admin or Device manufacturer.

Press Enter to try again. Press F8 to Startup Settings Press F9 to use a different operating system

This is basically what I'm seeing.

whadever said

Today I turned on the computer, it was up to 26% of the update (I'm assuming it was for firefox) and now I have a screen that says:
Recovery
You PC/Device needs to be repaired

I've never seen Firefox schedule an update for when Windows starts up. That may well have been a set of Windows updates.

whadever said

Yes I tried rebooting but now the recovery screen is the only thing that appears. I haven't even gotten to the log in screen of Windows 10 yet.

I assume you are posting from a different computer?

This could be a hardware failure with the disk, or it could be some kind of malware infection. Both of those problems are somewhat out of our league.

Can you check with your computer manufacturer on whether there is a nondestructive way to get the computer running normally? If they can only offer options that completely wipe the disk, that's a problem if you don't make regular backups. In that case, you could consider starting fresh with a new hard drive and extracting the data out of this current one without trying to boot Windows off of it.

For potential malware, please try the specialized forums listed in the earlier-linked support article. They may have your download a tool, burn it to a CD, then boot up using the CD to analyze the situation. Or maybe you can do it from a USB flash drive, but either way, it's something I don't have experience with.

Thanks for the additional error text. Web search turns up a lot of suggestions:

Your PC/Device needs to be repaired A required device isn't connected Error Code: 0xc000000f recovery tools - Google Search