Windows Defender is the Master
 

Asking for input on a problem I am hitting. Its a PC with SSD as C and WD 2TB HDD as E. 8GB of RAM (one recently failed) running Windows 10 Home 64 bit. Age of motherboard and Intel i7 processor and Ramos SSD now 2 years. All programs genuine. Avast antivirus installed and run. The problem exists also with the Western Digital Drive disconnected.

My problems stretch back 10 days. The computer was crashing about every two hours, message will report fault to Microsoft, etc. Event log was about 1200 errors in a five day period. Next day the PC was crashing often before I could log in. Anything important is not on the SSD so I made a clean install of Windows 10 home. Updates done, installed MS Office 32 bit Home and Business. Large amount of updates four hours on a good Internet. Yesterday, 16 December, all work on the PC was normal. I was sorting photos individually.

Today the computer crashed even before log on, about every 20 seconds. My log on PIN was not accepted but was reset via my Microsoft account. A pop up came up saying Windows could repair my SSD which I accepted. Computer now stays on and no crashes.

However Windows Defender has become the absolute master. I cannot open Task Manager, Avast is turned off continually by Defender. MS Office has been disappeared from the program list, does not open, and only scraps remain in Windows. Safe Mode is non functional. Downloads of my genuine programs on line blocked by Defender. The installer files it claims to be corrupted. Event Viewer will not open.

System Recovery has been set to zero by Defender. WiFi connection dropping out often.

I suspect a virus but Windows Defender will not allow me to connect to online virus scans nor use Avast.

If not a virus could the Motherboard be at fault, the SSD or Intel i7 Processor be faulty? My bets are on the virus.

The only option I see is to do another clean install of Windows. Nothing of importance is on C drive - the SSD.

Any input on this problem is appreciated.

Motherboard.

Or a virus purporting to be MS Defender.

Your initial symptoms sounded like a memory problem to me so I'd be suspicious of the remaining stick even though it seems ok now.

A failing power supply can also cause random failures.

Repairing an SSD generally involves marking corrupt areas as unusable and marking the files that were stored there as deleted. It's therefore likely that your disk is missing files which might cause surprise behaviour.

Your idea of reinstalling Windows is a sensible one,

Also, I wouldn't run two different virus scanners. They tend to fight each other. Once you get control back I'd disable one or other of them.

I would think of replacing the C drive SSD rather than just another reinstall of windows. Prices have come down so much that it's not a significant cost.

Did all the problems appear after the RAM failure?

Does it stay up in safe mode? If it does that points at a driver.

Does your BIOS have a RAM check function? If not try memtest64 in safe mode.

FWIW the Windows 10 update that dropped last week has been more disruptive than normal.

My apologies for a slow update. The problem was caused by a failing SSD drive. I replaced it and reloaded Windows and all is well.

This is a must, AV programs can often see AV signature files as malware, so if you are going to run more than one, make sure you white list both AV program and its signature files.

A few general thoughts:

1) Computer power supplies have limited extra current supply capacity. So adding extra electronics - e.g. extra memory to your computer without a larger capacity power supply can cause voltages to dip which can lead to problems with software crashing and resetting.

2) As I understand it, Windows Defender is the only virus protection you need. Defender is written by Microsoft themselves, who obviously have a vested interest in keeping their customers' computers healthy. Microsoft obviously know and have access to their entire Windows OS source code, so Defender is fully integrated and fully compatible. Updates for Defender are regularly published by Microsoft as new viruses and security threats are detected. Defender is free with legal copies of Windows OS, and can be configured to automatically update. So why use anything else ? I am told that Microsoft are not allowed to advertise Defender owing to competition rules ?

3) When computers have most of their memory filled, they can slow down significantly - even though there is some capacity left. To operate normally, computers shunt data in and out of their memory all the time, but when that memory is getting full, the computer can slow down and behave weirdly. I had this recently with an iMac, which although it had 10Gb of disc space left, was behaving very oddly and slowly - occasionally blanking the whole screen and not typing letters as I pressed the keys, but suddenly adding them after a couple of seconds delay.

4) Third party software can cause problems. Software that is available from the manufacturer's site will have been checked and vetted and approved by the manufacturer to work with their OS source code and integrate with their computers. 3rd party software won't necessarily have been through this process - especially if not downloaded from the Manufacturer's site.

4a) Third party software could contain malware and viruses hidden inside an innocent seeming application.

4b) Third party software might not be as robust as Manufacturer's Apps and might therefore allow hackers a 'way in' to your computer, even though the App they use to sneak in might itself be innocent and benign.

Based on the complexity of your situation, it seems there could be multiple factors contributing to the issues. While a clean install of Windows may help, there are several steps you might want to consider before going down that route again:

1. Hardware Diagnostics:
   
   • Test your SSD using dedicated tools like CrystalDiskInfo or Samsung Magician to check for errors or failing sectors.
     
   • Run diagnostics for your RAM using tools like MemTest86, as one module has already failed.
     
   • Check motherboard and processor temperatures to rule out overheating issues using software like HWMonitor.
     
2. System File Integrity:
   
   • Run
     Code:

     ---

     sfc /scannow

     ---

     and
     Code:

     ---

     DISM /Online /Cleanup-Image /RestoreHealth

     ---

     commands in Command Prompt to repair corrupted system files.
     
3. Windows Defender and Antivirus Conflicts:
   
   • Temporarily disable Defender's real-time protection in settings to regain control over Avast. If that works, verify the compatibility between Defender and Avast.
     
   • Boot into Windows Safe Mode using
     Code:

     ---

     Shift + Restart > Troubleshoot > Advanced options

     ---

     to troubleshoot further if Safe Mode becomes functional.
     
4. Virus Check:
   
   • Use a bootable antivirus disk (e.g., Kaspersky Rescue Disk) to scan your PC offline and rule out malware.
     
5. Event Log Review:
   
   • Identify recurring error codes in the Event Viewer (once accessible) to pinpoint the root cause.
     
6. Motherboard and SSD Suspicions:
   
   • If hardware diagnostics reveal no issues and viruses are ruled out, the motherboard could have failing components, or the SSD controller might be at fault.