I can't turn Windows Defender back on

tomasperez94

Honorable
Dec 22, 2013
27
0
10,530
I have a Windows 8.1 64-bit laptop. Yesterday, I wanted to download a program called MagicDisc (http://www.magiciso.com/tutorials/miso-magicdisc-overview.htm) and whenever I tried to install it, it gave me an error saying that I needed to run the program as administrator. I did that and it gave me the same error over and over as I tried it multple times. So I researched the problem via googe and I found out that it was my anti-malware software preventing me from installng it because it is an unsigned driver.
I found a solution and that was to go to the charm bar>Settings>Change Pc settings>Update and Recovery>Recovery>Under 'advanced startup'>Restart now. When it was restarting, a menu appeared with a couple options, I clicked on 'Troubleshoot', then another menu popped up and I , clicked on 'Advanced Options' then another one came up and I clicked on 'Windows Startup Settings' then something came up I clicked on Restart. The starting screen appeared and it loaded and a menu with a couple options came up and I pressed the 7th option which was 'Disable driver signature enforcement'.
The computer started and I clicked on the up arrow(Show hidden icons) button on the taskbar and right clicked on the AVG (AVG antivirus Free 2014) icon and then I disabled it for 5 minutes. I then proceeded to install MagicDisc once more and it worked! It installed with no problem. Then, I wanted to undo what I did, so I re-enabled AVG and did the same thing I did before by restarting the laptop and I saw that there was no option to enable driver signature enforcement again. When the computer started up I researched how to turn it back on and I got half of the answer:
Go to run and type 'services.msc' and then scroll down to Windows Defender, right click and click on Start.
I did just that and when it was almost done loading or finished loading, it gave me an error message:
Error 577 : Wnidows cannot verify the digital signature for this file. A recent hardware or software change might have installed a file that i signed incorrectly or damaged, or that might be malicious software from an unkown source.
Even though I uninstalled MagicDisc, it said it, I'm not sure how to fix it.
I cannot start the program and there is nothing I can find on the internet about my situation.
Thank you in advanced for your time and help.

Regards,
tomasperez94
 
Solution
You might have to do a refresh, renew or clean install of windows as there does not seem to be any way to reinstall windows defender. I cannot find a standalone or online installer for it anywhere although there is an offline windows defender application that will allow you to do scans in the event of a corruption or infection. You might be able to make some changes using that. http://windows.microsoft.com/en-us/windows/what-is-windows-defender-offline
What you probably need to do, if you didn't already and if so my apologies, but you need to get back to that advanced screen in the troubleshoot menu while restarting like you first did by going to charm bar>Settings>Change Pc settings>Update and Recovery>Recovery>Under 'advanced startup'>Restart now. Then uncheck everything you checked the first time and restart. That should hopefully bring back normal operation. You're starting in a different mode of windows until you undo those changes. Also, you will probably need to go into your anti-virus or malware program and make an exception for the file that's triggering the response.
 
You might have to do a refresh, renew or clean install of windows as there does not seem to be any way to reinstall windows defender. I cannot find a standalone or online installer for it anywhere although there is an offline windows defender application that will allow you to do scans in the event of a corruption or infection. You might be able to make some changes using that. http://windows.microsoft.com/en-us/windows/what-is-windows-defender-offline
 
Solution

tomasperez94

Honorable
Dec 22, 2013
27
0
10,530
I have finally given up. I could not find anything to get it back. But I do have an anti-virus program (AVG). So, there shouldn't be a need to install a clean version of windows.
Thank you for your help and have a great day.

Regards,
tomasperez94
 
If you have AVG antivirus installed you cannot access any area of windows defender. You failed to mention this before. Windows 8 and 8.1 automatically deactivate windows defender if you install another anti-virus program. If you uninstall the AVG you should be able to access the windows defender application.