I am writing because I recently had a problem with the software encryption in BitLocker. Indeed, following Microsoft's newsletter, I decided to test the new Windows 7. Under this OS, I decided to encrypt all data that was on my external hard drive. Since the release of Win 7 was limited in time, I'm back in my original OS (Windows XP). But like when I reconnected my hard drive the OS did not recognize, since it was encrypted. So I again reinstall Win 7 to regain access to my hard drive when I want to access my hard drive, it asks me the "key recovery" rather than the password I had configured originally. The problem is that the file with my key recovery is on the hard disk which I cannot access. Does someone could help me solve this problem, which frightens me? I fear I have lost all my data and my pictures. Is there a way to regain access to my hard drive? Or regenerate the key to recovery. Thank you in advance for your invaluable help!