You can try this:
Run certmgr.msc see what it finds
or
To import a certificate, run Microsoft Management Console (MMC) and add the Certificates snap-in. When prompted, select My user account. Navigate to the Personal\Certificates store, right-click the details pane, and select All tasks\ Import certificate. Then, point the wizard to your slaved disk and see what you get.
You can also run cmd: cipher /? see what that does for you
Or
here is a MS "tool" and help file that can give you some info on your EFS files:
http://www.microsoft.com/windows2000/techinfo/reskit/tools/existing/efsinfo-o.asp
Have you (admin) tried just removing the properties\advanced encryption atribute?
You can also search your slave drive fora .pfx file and if found drag it over and right click on it and hit "install PFX"
Next
Next then enter password from key(EFS from slave)
Next then hit "Place all certicicates in private store"
hit browse
personal, ok , yes, ok
you should then be able to open them all .
I just use the elmcomsoft advanced EFS recovery and EFS melts like butter, which is why its pretty much worthless in my eyes.
But it is $99 and you have to consider that. But if you get say $80 per hour for running that on EFS files, its worth it
Wanted to add that one thing you have going for you is that you know by using the demo that your files are in fact intact and recoverable, so that is a good thing, so keep plugging away and you should be able to get your files back.