I'm seeing the same defect "TurboTax is already running under another account", when there is no other user. I'm running win10 home, 64bit , v1803, build "17134" "1069", attempting to install/run standalone TT2019premiere
Tried running TT as admin, same error.
I also had TT2018 installed(always ran fine), so, thinking that may be confusing TT2019, I uninstalled both it and TT2019. I also manually removed TT remnants in C:\ProgramData\Intuit , C:\Program Files (x86)\TurboTax, and {user}\AppData\Local\Temp\ . Did a full shutdown (and tried intuit's recommendation to also shutdown/reboot the router, etc.). Starting from a clean reboot, I reinstalled TT2019. Same error "TurboTax is already running under another account". There is no other windows account logged in let alone running anything. (there is however a Cygwin instance running separately). This is clearly not a "spontaneous connectivity issue".
Looking at content in the session log file ( {user}\AppData\Roaming\Intuit\TurboTax\TY19\ErrorLog\ ) , it includes this info:
------------------------------------------------------------------------
...
2019.41.1.24 ERROR TurboTax -
System.ComponentModel.Win32Exception (0x80004005): Access is denied
at System.Diagnostics.ProcessManager.OpenProcess(Int32 processId, Int32 access, Boolean throwIfExited)
at System.Diagnostics.NtProcessManager.GetModuleInfos(Int32 processId, Boolean firstModuleOnly)
at System.Diagnostics.NtProcessManager.GetFirstModuleInfo(Int32 processId)
at System.Diagnostics.Process.get_MainModule()
at TurboTax.SingleInstance.ActivateOriginalInstance()
...
2019.41.1.24 INFO TurboTax -
SingleInstance.ActivateOriginalInstance assuming that we are already running as another user
------------------------------------------------------------------------
and here're some possibly relevant excerpts from C:\ProgramData\Intuit\TurboTax\MSI\TY19\Logs\20191205_TTINSTALLER.log :
------------------------------------------------------------------------
.NET 4.5.2 Full is already installed
FixupMsiexec1719():: WriteRegistryValue(MSIEXECCA64NAME) failed.
Not running action 'Files - .NET Framework 4.5.2 (64-bit)' for product '.NET Framework 4.5.2' because the OS condition does not match
------------------------------------------------------------------------
I'm thinking TT might be confused by the Cygwin installation that's also running on this system, or maybe it's a windows update conflict.
So I tried installing on another similar system that does not have Cygwin, and there was no error, it initiated normally, did updates, and proceeded to the activation key entry (which I did not do because I want to run TT on the other intended system, not a sandbox).
Would be interested to hear what Intuit support would have to say about this, particularly the Win32Exception (0x80004005).
