Hello. I have such a problem ... the point is that I can't download anything from the Internet ... the problem is probably windows defender which I have somehow turned off and now it cannot be turned on again. When downloading, no matter what file, the message "Failed - anti-virus scan failed" pops up. Is there any way to activate this antivirus through the registry or some other way? If I downloaded another antivirus, would it work and I would be able to download files?
I do not know if I did everything correctly, but I made the file, entered it all, the program repaired ... but unfortunately I still can't download anything because there is a failure at the very end (scanning ...)
The result of repairing Farbar Recovery Scan Tool (x64) Version: 20/06/2018 Started by artur (06/25/2018 19:53:23) Run: 2 Run from F: \ Uploaded profiles: artur (Available profiles: artur) Start Mode: Normal ==============================================
This message is displayed in all browsers IE, Firefox, Chrome? Or only Chrome?
If only in Chrome, download the bookmarks, uninstall Chrome and delete the profile directory from C: \ Users \ artur \ AppData \ Local \ Google \ Chrome \ User Data \ Default, reinstall Chrome after it is done.
Run regedit, go to HKEY_LOCAL_MACHINE \ SOFTWARE \ Microsoft \ Windows \ CurrentVersion \ Policies \ Attachments and change "ScanWithAntiVirus" (REG_DWORD type) from 3 to 1
✨ The user reported an issue with downloading files from the Internet, suspecting that Windows Defender was disabled and could not be reactivated. The error message "Failed - anti-virus scan failed" appeared during downloads. Various solutions were proposed, including scanning the system with Malwarebytes and using the Farbar Recovery Scan Tool (FRST) to generate logs for further analysis. A registry modification was suggested to change the "ScanWithAntiVirus" setting from 3 to 1, which ultimately resolved the issue, allowing the user to download files successfully. Generated by the language model.
Why it matters: This resolves system-wide download failures caused by Attachment Manager policy conflicts without reinstalling Windows.
Quick Facts
Registry fix: HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Attachments → ScanWithAntiVirus (REG_DWORD) = 1 [Elektroda, Kolobos, post #17296854]; see Windows Attachment Manager policy reference “Windows Attachment Manager”.
Malwarebytes scan example: 282,491 objects scanned, 15 threats quarantined, ~1m26s runtime on Windows 10 build 17134.112 [Elektroda, Masakra93, post #17295951]
Chrome-only fallback: remove profile at C:\Users\\AppData\Local\Google\Chrome\User Data\Default and reinstall Chrome [Elektroda, Kolobos, post #17296458]
Group Policy can reapply settings about every 90 minutes (+0–30 min offset) in domain environments “Group Policy refresh interval”.
Why do I get "Failed antivirus scan failed" for every download on Windows 10?
Windows uses Attachment Manager to notify antivirus when saving downloads. A mis-set ScanWithAntiVirus policy can break this handoff and block downloads in all browsers [Elektroda, Kolobos, #17296854; “Windows Attachment Manager”]. In the thread, changing ScanWithAntiVirus to 1 fixed the issue immediately [Elektroda, Masakra93, post #17297813]
How do I fix it fast via the registry?
Three steps: 1. Open regedit as admin. 2. Go to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Attachments. 3. Set ScanWithAntiVirus (REG_DWORD) to 1, then reboot [Elektroda, Kolobos, post #17296854] "Run regedit, and change 'ScanWithAntiVirus' from 3 to 1" [Elektroda, Kolobos, post #17296854] Back up the registry first “Back up the registry”.
Did this registry change actually work for the OP?
Yes. After setting ScanWithAntiVirus from 3 to 1, the OP confirmed downloads worked again: “Thanks, it finally works” [Elektroda, Masakra93, #17297813; #17297815].
Should I clean malware/adware before changing the registry?
Yes. The OP quarantined 15 threats; AdwCleaner then reported none; downloads still failed until the registry fix [Elektroda, Masakra93, post #17295951] "On another computer, download Malwarebytes and AdwCleaner and scan" [Elektroda, kindlar, post #17295908] This ensures no active adware interferes.
How do I run Malwarebytes and AdwCleaner like in the thread?
Install Malwarebytes, run a full scan, and quarantine findings; example: 282,491 objects scanned, 15 threats quarantined [Elektroda, Masakra93, post #17295951] Then run AdwCleaner; it should report none if clean [Elektroda, Masakra93, post #17295951] Tools: Malwarebytes (trial), AdwCleaner (free) [Malwarebytes; “Malwarebytes AdwCleaner”].
What if the registry value keeps reverting to 3?
A Group Policy might enforce the setting. Check Local/Domain policy: Windows Components → Attachment Manager → Notify antivirus programs when opening attachments “Windows Attachment Manager”. Domain policies refresh about every 90 minutes plus a random offset “Group Policy refresh interval”. Edit the policy or ask IT.
Can leftover thirdparty antivirus cause this?
Yes. Remnants can set restrictive policies. The FRST fix removed Arcabit and mks_vir traces and cleared Defender policies, yet downloads still failed until ScanWithAntiVirus was corrected [Elektroda, Kolobos, #17296419; Masakra93, #17296448].
How do I try the FRST approach shown in the thread?
Download FRST, run scans (FRST.txt and Addition.txt), then use a tailored Fixlist from a trusted helper [Elektroda, Kolobos, post #17296005] In the thread, a fixlist cleared Defender policy keys and leftovers, but the final fix was the Attachments value [Elektroda, Kolobos, #17296419; Masakra93, #17296448].
Is there a Group Policy (GUI) way instead of editing the registry?
If available, open gpedit.msc. Go to User Configuration → Administrative Templates → Windows Components → Attachment Manager. Set “Notify antivirus programs when opening attachments” to Enabled “Windows Attachment Manager”. This corresponds to ScanWithAntiVirus = 1 [Elektroda, Kolobos, post #17296854]
Will installing another antivirus fix blocked downloads?
Not necessarily. If Attachment Manager cannot notify any AV due to policy, downloads fail regardless of product [Elektroda, Kolobos, #17296854; “Windows Attachment Manager”]. Correct the ScanWithAntiVirus value first [Elektroda, Masakra93, post #17297813]
Any precautions before editing the registry?
Create a restore point and export the key. Editing the registry incorrectly can cause system issues “Back up the registry”. Use an admin account and document changes [Elektroda, Kolobos, post #17296854] Edge case: corporate EDR or policy may block changes “Group Policy refresh interval”.
