If you are unable to open a file downloaded from the internet, or received as an email attachment or getting an error while trying to open it, it’s likely because the file in question is blocked by Windows 10.
When a file is blocked by Windows 10, you need to right-click on the file, click properties and check the Unblock option under the General tab to unblock the selected file.
What is Attachment Manager in Windows 10?
There is a security feature called Attachment Manager that blocks unsafe files downloaded from the internet, received via attachments, or transferred from another computer from opening on your computer.
The Attachment Manager in Windows 10 is designed to protect Windows and your data from unsafe files that you might have downloaded or received as an attachment with an email.
If the Attachment Manager finds that a file is unsafe, it prevents Windows and installed programs from opening it or displays a warning message before you open the file.
Depending on the type of the program that you are using to download files, the type (file type) of the downloaded file, and the security settings of the Web content zone, Windows will either prevent or warn you when you try to open the file.
Like everyone else, if you often download files from the internet or receive files as email attachments, you might want to disable or stop Windows 10 from blocking the file downloaded from the internet.
Since Windows 10 does not offer a way to disable the Attachment Manager via Settings or Control Panel, we need to manually edit the Registry to disable the feature.
Complete the given below directions to turn on or off the Attachment Feature in Windows 10.
Turn on or off the Attachment Manager via Registry
Step 1: Open the Registry Editor by typing Regedit in the search box and hitting the Enter key.
When you get the User Account Control prompt, click on the Yes button.
Step 2: In the Registry Editor, navigate to the following key:
If the Attachments key is absent, right-click on the Policies key, click New, click Key and then name it as Attachments. And if the Attachments key is present, skip to the next step.
Step 3: Now, select Attachments key in the left pane. On the right-side, perform a right-click, click New and then DWORD (32-bit) Value and name it as ScanWithAntiVirus.
Step 4: Finally, double-click on the newly created ScanWithAntivirus value and change its value data to 1 to disable the Attachment Manager in Windows 10.
Close the Registry Editor. Save your work. Sign out and sign in, or restart your computer to apply the change.
To enable the Attachment Manager via Registry
Step 1: Navigate to the following key in the Registry Editor:
Step 2: On the right-side, double-click on the ScanWithAntivirus value and change its value data to 3.
Turn on or off Attachment Manager via Group Policy
Note that Group Policy Editor is not part of the Home edition. Home edition users need to use the Registry method mentioned above.
Step 1: Type Gpedit.msc in the Start/taskbar search field and press Enter to open the Group Policy Editor.
Step 2: In the Registry Editor, navigate to:
User Configuration > Administrative Templates > Windows Components > Attachment Manager.
Step 3: On the right-side, perform a double-click on the Do not preserve zone information in file attachments policy to open its properties.
Step 4: Select Enabled option. Click the Apply button to save the change.