Windows Defender Won't Turn On

TUnitG6

New Member
Messages
10
I'm running 8.1.

When I try to run Windows Defender through services (since it is set to manual and turned off), I get the following message:

Windows could not start the Windows Defender Service service on Local Computer.

Error 577: Windows cannot verify the digital signature for this file. A recent hardware or software change might have installed a file that is signed incorrectly or damanged, or that might be malicious software from an unknown device.

I can't get Windows Defender to start through the Action Center. When I turn it on, it just brings me to the system32 folder.

Any ideas? Do I need to do a clean install? I used to have avast installed, but have uninstalled it. If I can't get windows defender to work should I install something else?

EDIT: I am running malwarebytes anti-malware. Do you think there's a conflict there?

Thanks!
 
Last edited:

My Computer

System One

  • OS
    Windows 8
    Computer type
    PC/Desktop
Hi there. Yes, there's definitely a conflict. Defender by default will automatically turn off when another AV is installed.

Is there a reason why you want to use Defender?
 

My Computer

System One

  • OS
    8.1 Pro X64
    Computer type
    PC/Desktop
    System Manufacturer/Model
    Acer T690
    CPU
    Intel Pentium D Dual Core
    Motherboard
    Acer/Intel E946GZ
    Memory
    2GB (max upgrade)
    Graphics Card(s)
    Intel Graphics Media Accelerator 3000 - PCI Express x16
    Sound Card
    Integrated RealTek ALC888 high-definition audio with 7.1 channel audio support
    Monitor(s) Displays
    Acer AL1917W A LCD
    Screen Resolution
    1440 X 900
    Hard Drives
    350 GB Seagate Barracuda 7200.10
    Thumb drives
    PSU
    Standard 250 watt
    Case
    Desktop 7.2" (183mm) W x 17.5" (445mm) L x 14.5"
    Cooling
    Dual case fans + CPU fan
    Keyboard
    Acer Windows PS/2
    Mouse
    Wireless Microsoft Arc
    Internet Speed
    54mbp/s
    Browser
    IE11
    Antivirus
    Defender
    Other Info
    Office Pro 2013 / Nokia Lumia 1520 Windows Phone 8.1DP GDR1
Thanks for the response. I didn't realize that Malwarebytes was considered as an AV.

There isn't a specific reason. Do you have any suggestions for AV software? Should I reinstall avast free?
 

My Computer

System One

  • OS
    Windows 8
    Computer type
    PC/Desktop
I use Defender. Used MSE since introduction. Never have a problem. Easy on system resources also.

You may be correct about Malwarebytes. Is it the pro version you have? If so, that may be a full-fledged AV which is not allowing defender to start.

Forum friends of mine, Robinb9 and others, know more than I do about this stuff. Please read through this thread: http://www.eightforums.com/showthread.php?t=29529.

PM Robin if you'd like. I'm sure she won't mind helping you.
 

My Computer

System One

  • OS
    8.1 Pro X64
    Computer type
    PC/Desktop
    System Manufacturer/Model
    Acer T690
    CPU
    Intel Pentium D Dual Core
    Motherboard
    Acer/Intel E946GZ
    Memory
    2GB (max upgrade)
    Graphics Card(s)
    Intel Graphics Media Accelerator 3000 - PCI Express x16
    Sound Card
    Integrated RealTek ALC888 high-definition audio with 7.1 channel audio support
    Monitor(s) Displays
    Acer AL1917W A LCD
    Screen Resolution
    1440 X 900
    Hard Drives
    350 GB Seagate Barracuda 7200.10
    Thumb drives
    PSU
    Standard 250 watt
    Case
    Desktop 7.2" (183mm) W x 17.5" (445mm) L x 14.5"
    Cooling
    Dual case fans + CPU fan
    Keyboard
    Acer Windows PS/2
    Mouse
    Wireless Microsoft Arc
    Internet Speed
    54mbp/s
    Browser
    IE11
    Antivirus
    Defender
    Other Info
    Office Pro 2013 / Nokia Lumia 1520 Windows Phone 8.1DP GDR1
Malwarebytes Pro does not interfere with MS Defender. You may have some residue from an incomplete Avast uninstall
 

My Computer

System One

  • OS
    win8.1 pro
    Computer type
    PC/Desktop
    System Manufacturer/Model
    Home built
    CPU
    3.1ghz PhenomII
    Motherboard
    ECS Elitegroup A880GM
    Memory
    4gb ddr3
    Graphics Card(s)
    ATI HD4250 (onboard)
    Hard Drives
    SSD for OS, HDD for data
I had the same problem with Defender. I had the Pro version of Malware bytes installed at the time. It is my understanding that the Pro version has a fire wall which will conflict with Defender and will therefore shut it down. After a lot of searching on the subject it was believed that when another firewall shuts down Defender you will no longer be able to turn it back on even if you un-install Malwarebytes. That is not necessarily a fact but there were some who believed that it was a possibility. I couldn't even do a refresh as a message popped up saying that the drive Windows is installed on is locked. What I finally had to do was to restore to the factory image (after backing up my data) and then put back windows 8 and then 8.1. I'm not suggesting that it will be necessary for you to do that, (I hope not) but that was what I ended up doing. As far as malware protection is concerned, I only have Defender.
 

My Computer

System One

  • OS
    Windows 8 Pro
    System Manufacturer/Model
    HP Pavilion g7-120us Notebook
    Memory
    8 GIG
There is a possibility that there are remnants of Avast left over. Did you use a uninstall tool to remove Avast? This article has a link to the Avast uninstall tool, as well as instructions on how to use it.

Avast Software Uninstall Utility Download
 

My Computer

System One

  • OS
    Win 7 32, Win 7 64 Pro, Win 8.1 Pro
    Computer type
    PC/Desktop
    System Manufacturer/Model
    It's a Dell, Dude.
    CPU
    Intel Caffinated Core Duo
    Motherboard
    Father is bored too.
    Memory
    4 GB
    Graphics Card(s)
    NVidia something-or-another
    Monitor(s) Displays
    24" HD TV/Monitor/Alternative Dimensional Viewing Portal
    Screen Resolution
    Fuzzy after a couple drinks
    Hard Drives
    2 or 3, depending on if it's a night they're arguing about having a "split personality crisis" because I partitioned the drive.
    Case
    Don't get on my case....man
    Cooling
    Scotch on the rocks on the weekends..
    Keyboard
    Mad Catz Cyborg V7. Or maybe Cyborg Catz Are Mad At V7's??? I know it lights up...far out.
    Mouse
    currently being stalked by the cat...
    Internet Speed
    Never fast enough...
    Browser
    Defeated by Mario...wait...OH...BRowser...
    Antivirus
    Various
There is a possibility that there are remnants of Avast left over. Did you use a uninstall tool to remove Avast? This article has a link to the Avast uninstall tool, as well as instructions on how to use it.

Avast Software Uninstall Utility Download

I think you are correct along with Frank and owenspal. And in reading the posts following the tutorial that mikeytg linked, one will see that others had problems with other AV Programs that didn't totally uninstall.

It's the typical sloppy-written uninstall programs that leave remnants behind such as program folders, executables, dlls, crap in the registry, etc. That's why the post their updated or specific uninstall programs on their sites.

This includes most developers including Microsoft. That's one thing I could never understand, especially Microsoft. Its like tearing down the building, removing the debris including the foundation, and leaving a hole in the ground. Ugh!

Rant over.....
 

My Computer

System One

  • OS
    8.1 Pro X64
    Computer type
    PC/Desktop
    System Manufacturer/Model
    Acer T690
    CPU
    Intel Pentium D Dual Core
    Motherboard
    Acer/Intel E946GZ
    Memory
    2GB (max upgrade)
    Graphics Card(s)
    Intel Graphics Media Accelerator 3000 - PCI Express x16
    Sound Card
    Integrated RealTek ALC888 high-definition audio with 7.1 channel audio support
    Monitor(s) Displays
    Acer AL1917W A LCD
    Screen Resolution
    1440 X 900
    Hard Drives
    350 GB Seagate Barracuda 7200.10
    Thumb drives
    PSU
    Standard 250 watt
    Case
    Desktop 7.2" (183mm) W x 17.5" (445mm) L x 14.5"
    Cooling
    Dual case fans + CPU fan
    Keyboard
    Acer Windows PS/2
    Mouse
    Wireless Microsoft Arc
    Internet Speed
    54mbp/s
    Browser
    IE11
    Antivirus
    Defender
    Other Info
    Office Pro 2013 / Nokia Lumia 1520 Windows Phone 8.1DP GDR1
There is a possibility that there are remnants of Avast left over. Did you use a uninstall tool to remove Avast? This article has a link to the Avast uninstall tool, as well as instructions on how to use it.

Avast Software Uninstall Utility Download

When I had my problem, as mentioned in post No. 6, it could not have had anything to do with Avast, because I had never installed it. I did have the Pro version of Malwarebytes. I am not suggesting that that would not apply in this problem but it was not the cause of the problem that I had. I cannot even say what caused the problem because I really don't know, but I suspect that it was Malwarebytes. I just know that after trying several other things, I had to restore my system to its factory settings. I even tried to restore an image that I had made earlier and I was unable to do that. I've restored images several times before and never before had the problem. And as i mentioned before, I couldn't even do a refresh. But whatever was causing the problem with Defender being locked was causing my other problems.
 

My Computer

System One

  • OS
    Windows 8 Pro
    System Manufacturer/Model
    HP Pavilion g7-120us Notebook
    Memory
    8 GIG
My ASUS laptop came with Mcaffee activated, and I want to run Windows Defender, since its FREE. I tried disabling the Mcafee firewall. But DEFENDER still wouldn't activate. It kept saying another AV is running, check security action center. It seems as though Mcafee has HIGHJACKED my machine, and trying to FORCE me to pay for their service. Any help will be much appreciated.
 

My Computer

System One

  • OS
    windows 8
    Computer type
    Laptop
    System Manufacturer/Model
    asus
    Antivirus
    mcafee
My ASUS laptop came with Mcaffee activated, and I want to run Windows Defender, since its FREE. I tried disabling the Mcafee firewall. But DEFENDER still wouldn't activate. It kept saying another AV is running, check security action center. It seems as though Mcafee has HIGHJACKED my machine, and trying to FORCE me to pay for their service. Any help will be much appreciated.

Uninstall Mcaffee & defender should work.
 

My Computer

System One

  • OS
    Windows 8.1.1 Pro with Media Center
    Computer type
    PC/Desktop
    System Manufacturer/Model
    Gateway
    CPU
    AMD K140 Cores 2 Threads 2 Name AMD K140 Package Socket FT1 BGA Technology 40nm
    Motherboard
    Manufacturer Gateway Model SX2110G (P0)
    Memory
    Type DDR3 Size 8192 MBytes DRAM Frequency 532.3 MHz
    Graphics Card(s)
    ATI AMD Radeon HD 7310 Graphics
    Sound Card
    AMD High Definition Audio Device Realtek High Definition Audio USB Audio Device
    Monitor(s) Displays
    Name 1950W on AMD Radeon HD 7310 Graphics Current Resolution 1366x768 pixels Work Resolution 1366x76
    Screen Resolution
    Current Resolution 1366x768 pixels Work Resolution 1366x768 pixels
    Hard Drives
    AMD K140
    Cores 2
    Threads 2
    Name AMD K140
    Package Socket FT1 BGA
    Technology 40nm
    Specification AMD E1-1200 APU with Radeon HD Graphics
    Family F
    Extended Family 14
    Model 2
    Extended Model 2
    Stepping 0
    Revision ON-C0
    Instruction
    Browser
    Opera 24.0
    Antivirus
    Avast Internet Security

My Computer

System One

  • OS
    Win 7 32, Win 7 64 Pro, Win 8.1 Pro
    Computer type
    PC/Desktop
    System Manufacturer/Model
    It's a Dell, Dude.
    CPU
    Intel Caffinated Core Duo
    Motherboard
    Father is bored too.
    Memory
    4 GB
    Graphics Card(s)
    NVidia something-or-another
    Monitor(s) Displays
    24" HD TV/Monitor/Alternative Dimensional Viewing Portal
    Screen Resolution
    Fuzzy after a couple drinks
    Hard Drives
    2 or 3, depending on if it's a night they're arguing about having a "split personality crisis" because I partitioned the drive.
    Case
    Don't get on my case....man
    Cooling
    Scotch on the rocks on the weekends..
    Keyboard
    Mad Catz Cyborg V7. Or maybe Cyborg Catz Are Mad At V7's??? I know it lights up...far out.
    Mouse
    currently being stalked by the cat...
    Internet Speed
    Never fast enough...
    Browser
    Defeated by Mario...wait...OH...BRowser...
    Antivirus
    Various
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