I am confused about the true nature of the hidden and/or encrypted relationship of the files in question
--- Were your hidden files were encrypted on your XP computer,
----if they were encrypted you would have received an encrytion key and should have been able to save that key or at least write it down
Now it appears they are encrypted using your WIN7 computer
--- Are you being asked for the encryption key?
--- Check out http://www.google.com/search?sourceid=navclient&aq=&oq=win+7+encrypted&ie=UTF-8&rlz=1T4ADRA_enUS492US495&q=win+7+encrypted+folder&gs_l=hp..0.0l188.8.131.52.12516...........0.&pbx=1
The reference to green colored icons appears to indicate they are encrypted
--- So how were they encrypted?
However, I'm going to imagine that encryption might not be the problem without actual proof so I googled "Microsoft Word can't open this file because you don't have the correct permissions to access the file location" and it gave me the following ideas from various searches none of which I saw encrypted files being mentioned
--- Can you use the external hard drive that is now connected to your WIN7 computer other than trying to access the files you wish to access?
--- Is it possible that your external hard drive has a different path on your WIN 7 than it had when using the XP: for example it’s probably drive “D” on the WIN7 & but was recognized as a different drive on the XP in which case the files you are trying to access have a different path in which case you will need to correct the path access .
--- Then fix the drive/path I suppose either on the external hard drive and/or on the file location path
--- You have fixed the ownership on the new computer but that still doesn’t deal with a different drive/path location
A thought just came to my mind
--- Can you drag one of those files from the external hard drive to your WIN7 Documents folder and see whether or not it will open from there?