A much better place to look is in:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\WindowsUpdate\Auto Update\RebootRequired
If the RebootRequired key exists, then one or more windows update needs a reboot.
This may be the thing that makes some MSIs balk and demand a reboot before doing anything.
(This is Windows 7, BTW)
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\WindowsUpdate\Auto Update\RebootRequired
If the RebootRequired key exists, then one or more windows update needs a reboot.
This may be the thing that makes some MSIs balk and demand a reboot before doing anything.
(This is Windows 7, BTW)