Thanks for the advice but unfortunately the uninstall and re-install on Windows 7 64 bit is to turn off .NET 3.5.1 (i.e. SP1 of 3.5) under Programs and Features then re-enable. You can't uninstall and re-install directly as you can with XP as .3.5 is part of the core OS.

So, as noted in my earlier reply I have already disabled .NET 3.5, rebooted and then re-enabled. According to MS this will repair the install. No luck.

I've also run the .NET repair utility (NetFxRepairTool.exe - which repairs .NET 1.0 through 4.5.1) and also installed .NET 4.5.2 just in case.
So .NET 3.5.1 and .NET 4.5.2 are installed and enabled and have been repaired. No change. I'm checking after each step by the way.

I've also run the .NET verification tool which has verified .NET 3.5.1 is installed correctly

Interestingly while running the 4.5.2 update (which stops .NET apps during install) I get the following event log errors which I haven't seen before so may or may not be relevant

Application 'C:\Program Files (x86)\SooloosControlPC\SooloosHelper.exe' (pid 5516) cannot be restarted - Application SID does not match Conductor SID..
and
Application 'C:\Program Files (x86)\SooloosControlPC\SooloosHelper.exe' (pid 5516) cannot be restarted - Application SID does not match Conductor SID..

Also to provide more information, if I kill the Soolosshelper and SyncCompanion processes and try to start Control:PC those processes start without issue and then ControlPC crashes as always. Not sure if this helps at all.

I think I have to try a full Windows repair next...

Thanks for all the help

MS200, UHD722, DSP5200(SL), Roon