Cannot open Security Essentials or Windows Defender

I have uninstalled and installed MSE but when I try to open it just flashes quickly on screen then goes away...?! What could be wrong. I tried to uninstall Defender but it won't let me. and yet I cannot open Defender from anywhere. I do not understand what is happening. I have been using this new system for a year now, and this is first time with this issue.

It started when I noticed a small flag icon in lower right of taskbar next to the speaker icon, it had a red/white X through it. When I tried to start the Security Centre, it said cannot be started.

I have all updates, running i5 Intel, 4gb ram, ATi 5770 VGA, 500gb HDD, 21" Samsung, Antec 900 case, 650W PS, Win 7 Home Prem.

Please help this old codger if you can, its MOST frustrating......I have enough grey hair, don't need anymore...


unclepine

First let's check for infection by installing, updating then running a full scan with Malwarebytes, if necessary in Safe Mode with networking.

If that balks you likely have a smart infection blocking it's known killers. Download, burn to CD or write to flash stick, boot and run a full scan with Microsoft Standalone System Sweeper


Once the system is disinfected if needed then boot into Win7 DVD Repair console or Repair CD to run Startup Repair repeatedly. It should automate System Restore and SFC but if not run them from the Recovery Tools list options Command Line: SFC -SCANNOW Run in Command Prompt at Boot
System Repair Disc - Create

Next try to uninstall and reinstall MSE, which should disable Defender once it takes effect. If not, disable Defender yourself in services.msc.

If you have chronic problem with MSE then install instead Avast 6 which is comparable.

gregrocker said:

First let's check for infection by installing, updating then running a full scan with Malwarebytes, if necessary in Safe Mode with networking.

If that balks you likely have a smart infection blocking it's known killers. Download, burn to CD or write to flash stick, boot and run a full scan with Microsoft Standalone System Sweeper


Once the system is disinfected if needed then boot into Win7 DVD Repair console or Repair CD to run Startup Repair repeatedly. It should automate System Restore and SFC but if not run them from the Recovery Tools list options Command Line: SFC -SCANNOW Run in Command Prompt at Boot
System Repair Disc - Create

Next try to uninstall and reinstall MSE, which should disable Defender once it takes effect. If not, disable Defender yourself in services.msc.

If you have chronic problem with MSE then install instead Avast 6 which is comparable.

Well, I tried all the suggestions and STILL the problem persists. If I could find my darn CD, I would do a complete re-install...!

Defender is disabled in Windows 7.

This may be a better choice to remove MSE.
How to manually uninstall Microsoft Security Essentials 2.0.1963 if you cannot uninstall it by using the Add or Remove Programs item

Uninstall MSE using one of the methods given.

Install Avast 6 which is comparable and easily interchangeable if one causes issues as rarely happens.

Let Defender prompt you to turn it on if it wants it. No worries either way unless it errors in the logs: troubleshooting steps

gregrocker said:

Uninstall MSE using one of the methods given.

Install Avast 6 which is comparable and easily interchangeable if one causes issues as rarely happens.

Let Defender prompt you to turn it on if it wants it. No worries either way unless it errors in the logs: troubleshooting steps

Well, I tried the Avast thing, uninstall and install MSE, scans do not show anything malware wise, and...I dunno whats left..?

Will Avast even run if you install it? Does it present the same issues?

If SFC will not repair the Security Center then the last resort before clean reinstall is a Repair Install.

For either you'll need the Installation DVD. I would borrow one from a friend, extract the ISO using ImgBurn, unlock all versions if required using eicfg removal tool, burn to DVD using ImgBurn at 4x speed. If you must download one, search Google for official Win7 ISO at My Digital Life to get a safe copy.

gregrocker said:

Will Avast even run if you install it? Does it present the same issues?

If SFC will not repair the Security Center then the last resort before clean reinstall is a Repair Install.

For either you'll need the Installation DVD. I would borrow one from a friend, extract the ISO using ImgBurn, unlock all versions if required using eicfg removal tool, burn to DVD using ImgBurn at 4x speed. If you must download one, search Google for official Win7 ISO at My Digital Life to get a safe copy.

Yes, Avast ran a full scan with no issues showed up. I did find my Windows 7 DVD, so if all avenues fail, I can reinstall OS. Is there a way to save all my faves, software, docs, etc., to put back on new install..? Sorry for asking, but this sort of stuff scares the beegeezus outa me...hate to lose a years worth of data and stuff....