I started getting a weird message "Encrypting file system - Back up your file encryption key"

Just had this yesterday - 4th Jan 2014.

A trojan has installed itself - even with Norton Internet Security installed :-(

Used cipher /U /N command in administrative Command Window to find the encrypted file called HPM3Util.exe in Startup folder which was a Trojan. Used Norton's Power Eraser to clean off.

Hope this helps anyone else...

I think I have resolved this. I ran certmgr.msc, and I have seen that there was a certificate under "Personal". That certificate was issued yesterday. The only thing I did yesterday was install Office 2010, and use it to save a document onto my SkyDrive (just out of curiosity).

I think that created the certificate, and Windows prompted me to save it.

Now I deleted that certificate, and I don't get the popup anymore.

What do you think? Is my explanation plausible, or could something else have happened?