ASCOM Platform Installation Error on Windows 10

I am in the process of installing a new computer in my observatory. It is never fun going through the mass of software installations, etc. that accompany replacing what was a smoothly operating system. I’m replacing the old PC, which I built from parts from an even older PC I used at home, because the BIOS stopped saving its settings. It is probably the battery on the motherboard, but after 7 or so years it is time for an upgrade.

I bought a new HP Envy Windows 10 64-bit machine at Costco. All the installations (The Sky, Maxim DL, PinPoint, ASCOM, etc.) seemed to go fine at home. But I ran into problems with ASCOM when I was setting up the PC in the observatory and checking connectivity. When I tried to connect to the mount from Maxim DL, ASCOM brought up an error window and then did not have an mounts to select. The Astro-Physics setup program worked fine and connected to the mount. I ran the ASCOM diagnostics program, which reported that it had “Completed function testing run: 1559 matches, 2 fail(s), 5 exception(s).” It was not at all clear what the issues were.

So I ran the installer and repaired the installation. That did not change anything, I was still getting the same errors. The ASCOM Profile Explorer also brought up error messages and then didn’t work. I then ran the Profile Explorer as an administrator. And it worked. Running Maxim as an administrator also worked. Running as administrator, however, is not a good long-term solution.

So I went to the ASCOM Yahoo! Group (it is linked from the ASCOM Support page) and searched there. Success! I found a thread with my exact problem and, after figuring out Yahoo! Groups navigation, found a solution. Apparently the installer did not set permissions properly on a certain registry key. Here is what to do, taken from the wonderful people on that Yahoo! thread. But be careful, editing the registry can kill your computer.

  1. Run Regedit (hit the Window key, type “run”, hit enter, enter “regedit”, hit enter, agree to changes)
  2. Back up the registry (File > Export, select a place to save and a name)
  3. Open HKEY_LOCAL_MACHINE then SOFTWARE\WOW6432Node (Note these instructions are for 64-bit Windows)
  4. Right click on ASCOM and select “Permissions” You may be prompted to allow Regedit to reorder the permissions, that is OK
  5. Scroll to the bottom of the list of groups and select “Users”
  6. Make sure the box next to “Full Control” is checked and click OK
  7. Close Regedit and you should be good to go

In looking back, there are a couple of places where I could have found the error in the diagnostic and installation logs.

At the bottom of the installation logs, there is a section that starts with “Error List.” Two lines below it is this message, which points directly to the error:

Error RegistrySecurity - Subkey SOFTWARE\Wow6432Node\ASCOM does not have full access rights for BUILTIN\Users!

There is also this section in the diagnostic log that points out the problem:

12:01:08.912 ScanEventLog 12/29/2016 11:43:45 AM ASCOM Platform Error 24 FinaliseInstall - Exception HKCR\ does not have CreatorOwnerGenericAccess!
12:01:08.912 ScanEventLog 12/29/2016 11:43:45 AM ASCOM Platform Error 24 FinaliseInstall - Exception HKCR\ does not have SystemGenericAccess!
12:01:08.912 ScanEventLog 12/29/2016 11:43:45 AM ASCOM Platform Error 24 FinaliseInstall - Exception HKCR\ does not have SystemSpecificAccess!
12:01:08.912 ScanEventLog 12/29/2016 11:43:45 AM ASCOM Platform Error 24 FinaliseInstall - Exception HKCR\ does not have AdministratorGenericAccess!
12:01:08.912 ScanEventLog 12/29/2016 11:43:45 AM ASCOM Platform Error 24 FinaliseInstall - Exception HKCR\ does not have AdministratorSpecificAccess!
12:01:08.912 ScanEventLog 12/29/2016 11:43:45 AM ASCOM Platform Error 24 FinaliseInstall - Exception HKCR\ does not have UserGenericAccess!
12:01:08.912 ScanEventLog 12/29/2016 11:43:45 AM ASCOM Platform Error 24 FinaliseInstall - Exception HKCR\ does not have UserSpecificAccess!

The Finalize Install log has these entries, which also point to the problem.

11:43:45.810 CheckHKCRPermissions HKCR\ does not have CreatorOwnerGenericAccess!
11:43:45.811 CheckHKCRPermissions HKCR\ does not have SystemGenericAccess!
11:43:45.812 CheckHKCRPermissions HKCR\ does not have SystemSpecificAccess!
11:43:45.812 CheckHKCRPermissions HKCR\ does not have AdministratorGenericAccess!
11:43:45.813 CheckHKCRPermissions HKCR\ does not have AdministratorSpecificAccess!
11:43:45.814 CheckHKCRPermissions HKCR\ does not have UserGenericAccess!
11:43:45.814 CheckHKCRPermissions HKCR\ does not have UserSpecificAccess!

My sincere thanks to the ASCOM Yahoo! Group contributors. I have memorialized their advice here so that it might be helpful to someone else.