My OS is Windows 10.(64 bit).  I have received an attachment in an email via Live Mail. When I try to open it, I get the message: Cannot open a PPS file with your present security settings. I have temporarily disconnected my AVG system, but to no avail. The message is now a file in documents but I still cannot open it. This message says: Unable to open using a 64 bit system - uninstall windows 2010 excel and word.
Would appreciate some assistance - thanks, Doug Coulson

Have you tried going to the File tab in Live Mail, then Options, then to Safety Options, then to the Security tab and make sure the "Do not allow attachments to be saved or opened that could potentially be a virus" checkbox is unchecked in the Virus Protection section? If you have this checkbox checked it will block all attachments (it does not try to detect viruses as it suggests).

I received this response from the original poster.

Reference my PPS query – Thanks Ray for your suggestion, but I had already tried this, but with no effect. I tried Downloads but still could not open it; likewise sending it to Documents. I turned off my AVG security again, but it did not help. I know the sender so the content will be bona fide. Any more suggestions?
Regards – Doug Coulson

The only thing I would suggest is that you contact the sender and figure out why you cannot open it. Maybe he used a newer program to make the file that is not compatible with your older program to open the file.