GUIDs are the Globally unique Identifiers used by windows to install and identify software; they are used in the registry to ensure that keys used that piece of software are unique, a normal guid will look like this {XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX} but this guid is only one of the ways software will identify it’s self in the registry. You can also have a compressed GUID which you can get from a normal GUID by following this process
The first group of eight hexadecimal digits are placed in reverse order:
ABCDEFGH becomes HGFEDCBA
The same is done with the second group of four hexadecimal digits:
IJKL becomes LKJI
The same is done with the third group of four hexadecimal digits:
MNOP becomes PONM
In the fourth group of four hexadecimal digits, every two digits switch places:
1234 becomes 2143
In the last group of 12 hexadecimal digits, again every two digits switch places:
Lastly remove all {} ans -’s
python function to do this for you
compress_guid=(lambda guid:"".join(map(lambda x: x[::-1],guid[0:3])+map(lambda x:''.join([x[i:(i+2):][::-1]for i in range(0,len(x),2)]),guid[4:])))
compressed GUIDs occur in various places in the registry common ones being
HKEY_LOCAL_MACHINESOFTWAREClassesInstallerProducts
and somewhere under
HKEY_CLASSES_ROOT