J. P. Gilliver (John) wrote:

So in short, Task Manager can't be made to work without passwords,
though their use can be made invisible (surely negating their effect).

Task *Scheduler* (not Task Manager) demands to know the login
credentials for the account under which an event will run. A blank
password is still a password but just how could YOU specify a blank
password? Not entering anything into a field doesn't actually equate to
entering blanks or a null value. It means you didn't enter anything.

http://support.microsoft.com/kb/310715

I believe if you schedule jobs in Task Scheduler to run under the SYSTEM
account that you don't need to add a password. Of course, these jobs
don't run under the privileges of your Windows account but get all the
privileges of the SYSTEM account.

You cannot use the GUI interface provided by the Task Scheduler program
to define jobs that run under the SYSTEM account. You have to use a
command prompt to run the 'at' command. To figure out the command
syntax for the 'at' program, run "at /?" at a command prompt (i.e., open
a command shell to load a console window and enter the command at the
prompt).

http://support.microsoft.com/kb/313565
"Note When you use the at command, the scheduled task is run by using
the credentials of the system account."