Not able to delete registry keys per the Symantec Endpoint Protection (SEP) client manual uninstall process.
"Error while deleting key"
This can be caused if there is an attempt to delete a registry key that contains embedded null characters. These characters are not visible when viewing a registry entry.
If this registy item is accessed from user-mode, it is not possible to open the key containing the embedded null string.
Details: It is not possible to manually create a registry entry with an embedded null character. This usually occurs due to a corrupt application install or similar. It is also possible for the Windows kernel to embed a NULL character in a string to form a complete key name.
To delete a registry key that contains an embedded null character, first replace the null character with another character. Accomplish this by using the RegDelNull tool from SysInternals.