Can TrueCrypt encrypt a drive already in use?

[rapid]

As the title says, does anyone know if TrueCrypt is able to encrypt a drive that's already been formatted and had files copied to it, without losing those files?

 

[AMD_Gamer]

Yes.

 

[mrgstiffler]

Yes.

And it takes a REALLY long time.

 

[rapid]

Fair enough, thanks for the replies

 

[AMD_Gamer]

And it takes a REALLY long time.

Maybe if you have a CPU that does not have hardware AES. I did my 80GB laptop sand took 20-30 minutes.