My flash drive with my bitlocker key died, and my work PC asked me to enter my Bitlocker recovery key to boot. No problem, went to the office, got the harcopy of my Bitlocker info out and typed in my 48 digit Bitlocker Recovery Key. "Wrong Key" reply. I checked, and the Recovery Key Identication on on my hardcopy that I printed out when I installed Bitlocker two years ago doesn't match the Bitlocker recovery Identification currently on the recovery screen. I realize I'm probably screwed, but how would the Key change over time without any action on my part?