If you are just getting a message telling you that you can not access the files you need to take ownership of them by following the directions here
http://tinyurl.com/3aw7
But a lot depends on what has been done here as if you have not backed up these files without encryption or just moved a HDD to a Slave or External Position and have reinstalled the OS on the same HDD your Encryption Key will have been destroyed.
If that's the case I'll just repeat M$ advice to the unwary [b]Find a Good Hacker[/b] and give them access to your data and allow them to break the encryption.
However if you have the original OS on a HDD you can save a copy of the encryption key by following the directions here
http://tinyurl.com/3cd8hf
However if you have performed a install or a repair install your data will be toast and cost you quite a lot to recover. The best option is to suggest a Data Recovery House and even there you are going to be looking at several Thousand $ to break the encryption and you'll have to find someone who specialises in this type of Data Recovery.
They will also need the original HDD to work from as well.
Col