Cannot run Windows Offline Scan

Question

Windows Defender said that I had some files that had Trojans in them and noticed my PC started acting weird. 

I tried to run a Windows Offline Scan through Microsoft Defender and I am able to say scan now and the UAC pop-up showsand I can click yes but then nothing happens.

I have checked other threads and tried to run it through PowerShell, Command Prompt and even WMIC (I have no idea what it means but it says it was supposedly successful).

I'm currently running the Windows 20H2 updat e and my Security Intelligence version is 1.327.1715.0. 

I have checked the event log and it's saying that it's only scheduled to run the reboot in Nov 2021 for some reason.

Could someone please advise me on what to do?

Answer 1

Hi UrSupremeOreo,

You have probably already identified the root cause for why Defender Offline will not run.

The reboot date being 2021. We know that before the Trojans occurred, your Defender was

able to recognize the correct date, because your intelligence definition is up to date.

The question is, why does the Event Viewer now report that it is 2021. If you check the Time

and Date, on your PC, is it correct?  Even if it is, the problem might still come from corruption.

Probably related to the malware that Microsoft Defender detected.

If you examine Defender's Protection History, can you determine if every Trojan that was

detected, was remediated completely, and placed into Quarantine?

In any case, it would be a good idea to perform a full scan on your PC, using the Windows Safety Scanner.  It uses the same definitions as Defender, and should detect and remediate the same

malware as Defender.  https://docs.microsoft.com/en-us/windows/security/threat-protection/intelligence/safety-scanner-download

Also, download a free copy of MalwareBytes, and do a full scan with it. Set it to "Scan for

Rootkits", and let it clean up all that it finds.   https://www.malwarebytes.com/mwb-download/

These two scanners will surely ensure that you no longer have any malware present.

If Defender Offline still refuses to scan, you will need to take further steps, in an effort to

remove any corruption  that may be present.

The SFC Scan is a good first step. You can run it from Command Prompt (Admin) by...

Clicking "Start" and type "cmd".  Select "Run as Administrator".  On the Command Prompt

screen type the following command and depress  <enter>.

SFC /scannow     <enter>  Allow time for the scan to finish. If it found any corruption, run it

                                            again, until it runs clean.

Exit    <enter>  to close Cmd Prompt.

Test Defender Offline again.  If it still fails with the date = 2021, you will probably need to

perform a Repair Upgrade to resolve the problem.

Repair Upgrade completely replaces your OS, while it retains your Apps and Files. After the

Repair, your PC is just as it was before the Repair, but without the corruption.

Repair Upgrade is a secure operation if your PC configuration is HDD only or SSD only.

A very few times in the past, the combination of the two, has been problematic.

If that is your configuration, you should create a System backup, as a precaution..

If you elect to perform the Repair Upgrade, you begin by downloading the Creation Tool here.

https://www.microsoft.com/en-us/software-download/windows10

Right click the downloaded file and select "Run as Administrator".

Choose "Upgrade this PC now", and the procedure will begin.

Answer any questions logically. And when asked "What to keep", ensure that OS and Apps & Files are both selected. They should be, already.

The procedure will run for about one hour.  Your PC will Restart several times.  Sometimes it

appears to be doing nothing.  Be Patient.  When it is finished, your sign in screen will appear.

Sign in and go to Windows Update, and "Check for Updates". After the updates are finished,

test Defender Offline again. It should work OK now.

Good luck,  Glen

Answer 2

Hi,

I'm Independent Advisor not Microsoft employee or support person. I have deep enough Windows knowledge and you may trust me. It's a pleasure for me to help others and I'll do all my best to help you.

You may try another off-line tool from other antivirus vendor e.g. Kaspersky Rescue Disk.