Thank you Srinivas. Unfortunately, your reply doesn't address my problem.
- I didn't explicitly encrypt the files in question, it happened occultly while I migrated from Win7 Pro to Win7 Ultimate.
- The ownership, at least nominally, of the file did not change.
- I am trying to access the file from an administrative account, yet Windows still asks for administrator permission. When I click 'continue' it returns with: "An error occurred applying attributes to the file ..."
- When I inspect User access, it tells me that I am the user (but with a '@' rather than a '/'), and gives me a certificate footprint.
- The file(s) in question are ordinary tab delimited text files (*.txt) containing experimental data.