>>> def decode(a):
...   a = bytearray(a)
...   for i in range(len(a)):
...     a[i] -= 1
...   print(a)


>>> test = "BCDEF=XJO8.Y75.DVDLPP&MNOPQ=Xjoepxt!8!Qspgfttjpobm&GHIJ=vtfs&UVWXYZ=XJO8.Y75.DVDLPP$$vtfsAAgc31bb63.2fd:.5e2g.c:34.g781:5::f715&st=0"

>>> test = test.split('&')
>>> for val in test:
...   decode(val.split('=')[1])
...
WIN7-X64-CUCKOO
Windows 7 Professional
user
WIN7-X64-CUCKOO##user@@fb20aa52-1ec9-4d1f-b923-f6709499e604
/