Windows 7 Forums
Welcome to Windows 7 Forums. Our forum is dedicated to helping you find support and solutions for any problems regarding your Windows 7 PC be it Dell, HP, Acer, Asus or a custom build. We also provide an extensive Windows 7 tutorial section that covers a wide range of tips and tricks.

Windows 7: Windows Defender starts and disappear right away...

09 Dec 2010   #1

Windows Vista Home Premium
Windows Defender starts and disappear right away...

I am running Windows 7 Ultimate and had run Windows Defender before successfully. Now, it is verified to be installed. I ran it as Admin by clicking on the Windows Security Essentials icon.

A screen appeared and disappeared in a flash. I went to "Turn your features ON or OFF" but did not see Windows Security Essentials or Windows Defender listed there for me to turn on or off.

I am able to pin Windows Security Essentials on my task bar but when double-click it, same problem occurred. Tried everything suggested online but no deal.

Any ideas to help me out?


My System SpecsSystem Spec
09 Dec 2010   #2

Windows 7 Ultimate 64-Bit

Hi there, run a system file check from elavated command prompt using the sfc /scannow. Restart and see if this helps! :)
My System SpecsSystem Spec
09 Dec 2010   #3
Borg 386

Win 7 32 Home Premium, Win 7 64 Pro, Win 8.1, Win 10

Try uninstalling it, d/l a new version of MSE and reinstall. That usually fixes the problem.
My System SpecsSystem Spec

09 Dec 2010   #4

Windows Vista Home Premium
Tried both suggested solutions...still same problem

Thank you very much for your suggestions, tezlewis and Borg 386.

I tried both. The scan did not detect any problem and I restarted the machine. No luck. I then uninstalled MSE, reinstalled MSE and restarted the machine. Same problem happened.

After MSE was uninstalled, I tried to install Windows Defender but got the following error:

"You do not need to install this software because Windows Defender is included in Windows Vista. You can access Windows Defender from the Security section of the Windows Control Panel"

1st of, I am running Windows 7, not Vista. I looked into the Security section but did not see Windows Defender on my list of "Turning features on and off" dialog.

Any other ideas to help me out?

Many Thanks...Mimi
My System SpecsSystem Spec
09 Dec 2010   #5

Windows 7 Home Premium 64bit

Might want to run a scan with Malwarebytes and/or Superantispyware.
My System SpecsSystem Spec
10 Dec 2010   #6
Borg 386

Win 7 32 Home Premium, Win 7 64 Pro, Win 8.1, Win 10

It is possible you have some sort of virus that is preventing it from starting.

However, if you are using MSE, Windows Defender should be automatically disabled by MSE. There could be a conflict there.

You could try taking out both MSE and Defender, then install only MSE. MSE incorporates the functions of Defender as well as an AV. Once you've removed Defender and install MSE, the problem might disappear.

Also, you could type services.msc, check the services and set Defender as Startup Type: Manual.

Just be aware that with MSE, you don't need Defender.
My System SpecsSystem Spec
11 Dec 2010   #7

Windows Vista Home Premium
Fixed 749 problem

Quote   Quote: Originally Posted by rvbfan View Post
Thank you very much, rvbfan. I ran both links you suggested above and picked up 749 problems and fixed them.

My anomalies are gone. Thank You! :)
My System SpecsSystem Spec
11 Dec 2010   #8

Windows Vista Home Premium
Could not delete Windows Defender

Thank you so much for your suggestion, Borg 386.

I had both MSE and Defender (not sure if its disabled or not). I uninstalled MSE. I could not uninstall Defender so I went to delete the Defender folder under Program Files.

It wouldn't let me. It says:

"You need permission to perform this action.
You require permission from TrustedInstaller to make changes to this folder..."

I fiddled with the ACL to try give it permission but to no avail.

How can I get rid of it before reinstalling MSE?

Many Thanks...Mimi
My System SpecsSystem Spec
11 Dec 2010   #9
Borg 386

Win 7 32 Home Premium, Win 7 64 Pro, Win 8.1, Win 10

Well Nokoyashi, looking at some articles, Some claim it cannot be uninstalled, but it can be disabled. I personally have never tried to remove it since MSE disabled it automatically.

If you installed MSE and Defender is sitting quietly in the background without any problems (disabled automatically), I would just leave it there. There's no need to use it once you have MSE in the system.

Just in case you are having some problems, I found some links that you could peruse, the 1st one has good info one it. I hope these links can help you out. Some refer to Vista, however most Vista instructions apply to Win 7 also.

How To Disable, Uninstall or Remove Windows Defender in Vista | Raymond.CC Blog

Remove Windows Defender from Vista System Startup

How to Disable (Remove and Uninstall) Windows Defender in Vista My Digital Life
My System SpecsSystem Spec
11 Dec 2010   #10
Hopalong X

Windows7 Pro 64bit SP-1; Windows XP Pro 32bit

You can't uninstall Defender from everything I have read.
It isn't an add-on.
Defender is part of the Win 7 OS.

As Borg386 stated it is automatically disabled when MSE is installed.
Also some other antivirus sofwares will disable it when they are installed.
That is what I have read but I don't know which ones at the moment.

My System SpecsSystem Spec

 Windows Defender starts and disappear right away...

Thread Tools

Similar help and support threads
Thread Forum
Windows starts very slowly, when it starts
I was trying to remove Windows Defender this morning as I'm running MS Security Essentials. I thought the two programs might be conflicting with each other. MsMpEng.exe was using over 260K of physical RAM which I thought was excessive. At one point I suspended the MsMpEng.exe process while in...
General Discussion
Security Defender / Defender Pro 2015 Virus/Trojan ?
Hello, Looked for a "Virus" sub-forum, but don't see any. So will post here, please. Last night, a horrible experience. Apparently some virus software organization put on PC something that takes over, completely and literally. Called Security Defender and Defender Pro 2015
System Security
Icons won't disappear when delete, only disappear when refresh!
Hello Guys! This is my problem: Icons won't disappear when I move to recycle bin, only when I click REFRESH it disappear, I scanned my computer and I found threats with my Anti-Virus, all threats are deleted! and the problem won't go! PLEASE HELP! :cry: P.S: I have explorer.exe error: not...
General Discussion
When computer starts wifi starts automatically?
Hello I bougth new Notebook Acer 5741G which has Windows 7 X64. When I start computer it always starts up automatically WiFi adaptor. Do you think is it possible to disable that function? I have tried to do that in many ways but I cant. Thank you in advance
Network & Sharing
Windows Defender starts maximized
When Windows Defender starts, it starts maximized and displays the status screen. I have to click the minimize or close button each time to get it to minimize. Is there a way to get it to start minimized so I don't have to manually do it?
System Security

Our Sites

Site Links

About Us

Find Us

Windows 7 Forums is an independent web site and has not been authorized, sponsored, or otherwise approved by Microsoft Corporation. "Windows 7" and related materials are trademarks of Microsoft Corp.

Designer Media Ltd

All times are GMT -5. The time now is 12:26.
Twitter Facebook Google+