|Use a Linux Live CD (such as Puppy Linux). Set your machine in BIOS to boot from the CD as first option. Put the Linux CD in the drive and boot. You can then use Linux to rename the files back again, assuming you know where they are located.|
Having said that, it seems odd to me that Windows let you rename them at all while it was running. How did you manage it and what on earth was your reason for doing so?
Long Range Golfer