Is there susch thing as a Write Protected Read Only registry key?

[Mojonba]

Here's my problem I'm trying to install Caere Omnipage 10. This program setups calls for another setup that installs Caere Sacn Manager v5. The Scanmanager setup tells me he cannot write to the registry value in HKEY_Local_Machine/Software/Caere Corp/*** Then I have to ignore thos errors and have problems with that programs. I've tried to delete that registry key but windows won't let me and it won let ScanManager's Setup to write either.
WTF is happening here?

 

[Delusion2001]

try restarting and doing that (disable all startup items). i myself have never encountered this problem