I'm sure anyone who regularly re-formats their computer (and uses Truecrypt) understands where I'm coming from here. I have to decrypt ~800GB of data so that I can re-install windows. It didn't use to be a problem (I had two hdds one for storage and one for OS) and both were encrypted (Though seperately) but when one began to die and I had to back everything up on to my main drive (I have a network drive I'm currently using for backups now) the entire system was encrypted meaning I have one drive that currently contains all my data. Thus in order to re-install windows (For my regular formats) I have to decrypt my entire drive. Now I just have to wait 36 hours.