This works for me in VFP9, Windows XP SP2. When I compare it to the encrypted version of the same file encrypted in vfp7, it matches. I must be missing something?

SET SAFETY OFF
lcstartfile = "myfile.txt"
IF FILE(lcstartfile)
   DELETE FILE (lcstartfile)
ENDIF

lcstartstring = REPLICATE("1234567890-=\~!@#$%^&*()_+|abcdefghijklmnopqrstuvwxyz,./<>?[]{}"+CHR(13),2000)
STRTOFILE(lcstartstring,"myfile.txt")

loCrypt = NEWOBJECT("_CryptApi",HOME()+"FFC\_Crypt.vcx")
IF FILE(lcstartfile)
   MODIFY COMMAND (lcstartfile)

   IF MESSAGEBOX('Encrypt File?',1+32+4096,'Encrypt') = 1
      =TestCrypt(.F.,lcstartfile)
      MODIFY COMMAND (lcstartfile)
   ENDIF
   IF MESSAGEBOX('Decrypt File?',1+32+4096,'Decrypt') = 1
      =TestCrypt(.T.,lcstartfile)
      MODIFY COMMAND (lcstartfile)
   ENDIF
ENDIF
IF FILE(lcstartfile)
   DELETE FILE (lcstartfile)
ENDIF
RETURN

FUNCTION TestCrypt
LPARAMETERS plReverse, pcfile

IF TYPE('pcfile') <> "C" .OR. !FILE(pcfile)
   RETURN .F.
ENDIF

IF plReverse
   lcString = FILETOSTR(pcfile)
   lcDecrypted = ''
   ? loCrypt.DecryptSessionBlockString(lcString, "x", @lcDecrypted )
   STRTOFILE(m.lcDecrypted,pcfile)
ELSE
   lcEncrypted = ""
   lcString = FILETOSTR(pcfile)
   ? loCrypt.EncryptSessionBlockString( lcString, "x", @lcEncrypted )
   STRTOFILE(m.lcEncrypted,pcfile)
ENDIF
RETURN