I'm 99% sure, at this point, that the answer is, "not possible." But I figured there are tons of smart people here who might be able to help me out, even if that help is just to validate that it's not possible.
About a year ago, I migrated my home computer to Windows Vista, with a clean install. The clean install is where I went wrong -- like an idiot (and I admit this), I did not back up the EFS key in use on a bunch of my financial and other sensitive files.
I copied all those files (as well as my other documents, source control repositories, etc.) to my second hard drive (formatted NTFS, so EFS stuck around) before the migration. Again, the EFS attributes stuck around, and -- because I'm a dork -- I not only didn't back up the EFS keys, but I also didn't remove the encryption from these files. (I would like to state at this point that the lesson has been learned; I don't even use EFS anymore at all.)
I've tried a variety of applications available online, including several paid apps, and none have had any luck. My hunch is that this is due to wiping and rebuilding the OS from scratch, as the SIDs of my user accounts obviously changed, and the EFS keys were simply gone, not part of the OS.
I'd like to get at these files, or at least be able to delete them without reformatting the drive they're on. :) Does anyone have any advice? (Again, even if "not possible" winds up being the answer. Something definitive.)