FATAL ERROR when upgrading from 4.0 to 4.1

[xplay]

I installed sos 4.0, and try to upgrade to 4.1, it show an error:

FATAL ERROR
Installation ended prematurely because of an error.

then the setup-program quited...

I cleaned all related data in the registery, and find that : the KEY
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Enum\Root\LEGACY_SOSSVRSVC.NET\
can't be deleted , further more nothing under this key can be modified! and the subKey
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Enum\Root\LEGACY_SOSSVRSVC.NET\0000\Control
is LOST!!!!

I tried to reinstall sos 4.0, it's still OK.

how will I do???

[lbauer]

So SOS 4.0 installed and is running?

Can you stop the SOS Server service, uninstall SOS 4.0 and then install SOS 4.1?