I fight is not the first day with a problem.
There is a command line for cmd:
schtasks / CHANGE / TN "my_task" / RU user_login / RP pass / IT
which changes the password for the task in the Windows Scheduler, but the problem is that when the command is executed, the item in the task “Perform for registered users only” is reset to “Perform regardless of registration”. That does not suit me very much, although I use the / IT parameter