Windows 10 Pro 64bit 1607 Update Deactivated FSX

My update to 1607 went smoothly yesterday...deferred for quite while...had to reinstall DisplayLink driver as expected. Started testing various apps. Found out that the update deactivated FSX Gold + Acceleration which was running fine on 1511. I have run FSX for many years. Tried a repair from the DVD which failed every time with an InstallShield error o cannot complete error. I tried an uninstall...was able to unistall Acceleraton pack but FSX itself will not unistall. The process starts but will eventually fails after the initial stage with the InstallShield error . Accel pack will not install as it now thinks FSX is not installed. I am at a loss. I am a 40 year computer technology professional but this one has me stumped. I tried everything on the Internet but nothing has worked. Anyone seen this issue...any fixes?

Try installing as administrator in Compatibility Mode say win7 or 8.1?

I have tried different compatibility settings...if I try a repair I get Error 1605: action only valid for installed products. and if I try the Remove I get "Failed to load DLL: GameuxInstallHelper. Setup launches but this is as far as it gets.

Long shot but tried installing or uninstalling in safe mode?
Also, anything obviously missing from before the upgrade such as DX9 or a specific version of Visual C++?
Just thinking of hoops I've had to jump thorough getting things to work in Win10.
Tried renaming the install shield folder and the running the installer again? as should recreate it.

Resolved...well it took several steps...had to manually search and delete any Microsoft Flight Simulator entry in the registry related specifically to fsx.exe. This allowed the Remove to work from the DVD. Then reinstalled FSX and activated. Launched and it worked. Then I installed the Acceleration pack. Launched and got the activation error again. Went into the registry and looked for the UpperFilters setting in the MS FSX registry key HKEY_LOCAL_MACHINE\SYSTEM\CURRENTCONTROLSET\CONTROL\CLASS
\{4D36E967-E325-11CE-BFC1-08002BE10318} and modified it..deleted the partmgr and typed PartMgr and restarted FSX with Accel Pack, it immediately asked for activation and entered the product key and it activated successfully. This was a 24 hour pain.....but back to normal after the 1607 update.