More about that at http://en.wikipedia.org/wiki/Encrypting_File_System
The good news is this can be decrypted. And if it's just some word password, the same company I'll mention does that as well.
It is however possible that it's just the old user/ownership issue noted at http://forums.cnet.com/7723-7588_102-585156/how-do-i-fix-permissions-to-access-files/?tag=contentBody;threadListing
http://lostpassword.com will walk you through the Word and EFS recovery.
My old desktop "died" (don't ask me what happened specifically - it just wouldn't boot), so I bought a new PC. Old one had Windows XP Media Center, new one has Windows 8 but I have an office computer with Windows XP pro.
I had pictures and documents in the in the "documents" folders for 3 users on the old hard drive. I successfully removed the old hard drive and now have it in a hard drive enclosures. I can access the files for the 2 users which did not require a password when using them on the old computer before it crashed. But I cannot access the document for the 3rd user, the only one which required a password when signing into windows on the old machine. I can see that user's folders, and can see that there are "picutres" "music" and "video" folders, but I cannot open them. I get an "access denied" message of some sort.
I've researched and it appears that I may have to "take ownership" of the old hard drive folder for the user name which had the password, but I'm not sure and when I tried using the instructions I found on the web, they don't match up with the screen/options and/or are not detailed enough to walk me through the process.
This has to be a common problem but I cannot find the right help.