I am running into strange issues with my Windows 10 work desktop. 2 weeks ago I was using the desktop and all of a sudden a custom task I created over a year ago started running (its scheduled to run at 9:00 PM, this was about 2:30 PM in the afternoon, the task is described in detail below). I can't use my PC while the task is running, so I rebooted and Windows came back up fine. I tried to look at the TaskScheduler history to figure out what happened, but task history was of course disabled (I re-enabled task history at the time). Looked through EventViewer as well and saw nothing else that would indicate why this happened.

Fast forward to today, I came into work and my PC was sitting at the login screen (unusual because this machine is only rebooted for updates, and I try to make sure its logged in whenever I leave). I try to login, and the screens just go to a black blank screen after entering password, the desktop never comes up. If I let it sit long enough (5-10 mins), the task in question will start running on the blank screen. If I ctrl-alt-delete, the screen comes up with the typical options. I try and open task manager from here and nothing happens. My first attempt to boot into Safe Mode works, only error I got was something like "cannot start app 'Get Started' with built in adminstrator account". Everything else seems alright.

Has anyone else seen this strange behavior with custom tasks defined from TaskScheduler? Or has anyone had their Windows 10 install hang after trying to login (enter password->hit enter->screens go blank nothing happens)?

I have made a custom task within TaskScheduler that does the following:
-Tries to start W32Time service (Windows Time Service) if its not running.
-Updates a Visual Studio 2010 project from SVN (using Tortoise SVN command line commands).
-Builds said project from the command line (devenv.exe).
-Copies Output files from Visual Studio project to regression test directories (using xcopy & copy).
-Runs a regression test program (Squish using javascript scripts) to test the built programs.
-FTP uploads results of Regression tests.

These commands are all contained within batch files. "TestRunner.bat" is the main batch file that calls other batch files and is run by the task I created. The second, third, fourth, and fifth bullets are contained in their own batch files (TestRunner.bat calls UpdateAndBuild.bat to update and build project, CopyFiles.bat to copy from project output to regression test dirs, FTPUpload.ftp is called at the end to upload results).