This is not new. But after upgrading to Windows 10 from Windows 8.1, I found that when trying to unzip a compressed folder that contained an executable file (.exe) and sent to me from a trusted source, I was presented the error below and the executable could not be unzipped and run. <Insert a frustrated "What?!?!" here>
Message: Windows Security Warning "Windows found that this file is potentially harmful. To help protect your computer, Windows has blocked access to this file."
I also had a very similar message when double clicking on Excel files that I had downloaded via web sites.
After messing around for a while, I found that if I chose to "Unblock" the file(s) in both instances, the error was resolved. The .exe would unzip and could be run as expected and the Excel file would open without issue.
You can do this relatively simply using these steps:
1. Right click on the file and choose Properties, then choose the General tab
2. Notice that in the bottom there is a Security message similar to this:
3. Select the option for 'Unblock' > OK.
4. The files should now be unblocked and allowed.
Now, this is a quick and handy workaround, but doing what I do every day it's not really feasible to continually be unblocking all files that would come to me in a way that may be deemed unsafe when I know they are. So, after further digging, I found that by setting a Local Policy on the machine, the files were not flagged as blocked to begin with.
Here's what I did to resolve this issue:
** Please note that these policies are there for protection deemed necessary due to things we all know that people with malicious intent may try. It's a good policy and myself (nor Microsoft) are in no way saying that you should do this to each and every machine you may work with. It's also something you'll need access and permissions to edit on your machine. So use this at your own risk. **
1. Open the Local Group Policy Editor (gpedit.msc)
2. Browse to: User Configuration > Administrative Templates > Windows Components > Attachment Manager
3. Locate the policy for: Do not preserve zone information in file attachments
4. Choose to 'Enable' the policy > OK
As the description explains, if you enable this policy setting, Windows does not mark the file attachments with their zone information.
5. Restart the machine.
While I hope this helps many of you, this will not solve all your issues you may encounter and is only concerning the examples I experienced myself and the specific policy that was needed for these examples. Happy computing!
* If you are getting a more application type of error message, check out this blog as a possibility:
Office documents may error when opened after a Windows 10 upgrade