This is very common error since the release of Windows 7 and Internet Explorer 8; we thought we had a major virus but this turned out not to be the case. There are some security settings that need to be tweaked inside the Internet Options to allow downloads again.
“your internet security settings prevented one or more files from being opened”
Problems Opening Files on LAN
You may get the “these files cannot be opened” error when opening files on a network drive.
Control Panel –> Internet Options –> Security Tab
I unchecked them all and it works! The “your internet security settings prevented one or more files from being opened” didn’t block me and I can now open files on network drives.
Problems opening files in Internet Explorer, Firefox & Windows Explorer
Setting these for both the Internet and Intranet settings should take care of the file open problems. The setting I discovered during my troubleshooting is “Launching applications and unsafe files”. This can be set in two places depending on your network setup.
Change the settings in Internet Options
This is an error from Internet Explorer security settings found under your “Tools” –> “Internet Options” –> “Security” tab –> “Local intranet” or “Internet”.
Make sure you can download files
You may also need to enable File download to get past the “these files can’t be opened” inside the Internet Properties.
Change this is Group Policy
If you operate in a domain you will need to add the settings to a new GPO to remove the “your internet security settings prevented one or more files from being opened” error from all network systems at once. This method worked for me.
Open your Group Policy Management Editor and either create a new IE8 Policy or use an existing one and go to User Configuration –> Policies –> Administrative Templates –> Windows Components –> Internet Explorer –> Internet Control Panel –> Security Page –> Internet Zone –> Launching programs and unsafe files
You should do this for both Internet zone and Intranet zone.
Well, the steps above solved my problem since I first posted this tip. I can’t help on a problem I cannot reproduce so my posting above is all I have to offer.
Hopefully the comments below can help everyone else. Thanks to Sebastian…