I' ve written a VB-program to change a set of passwords on remote
servers. The program should change the passwords of scheduled task
too.

It's looking like there are two not fully compatible mechanisms to
schedule Tasks: the AT-command and the GUI-Interface.
Jobs planned with the AT-commando are shown in the GUI - Jobs planned
with the Task Schedule Wizard are not shown by the AT-commando (!).
Furthermore there is no possibility to change the user and password of
the executing user with the AT-command. With the GUI-Interface you can
change user and password.

The "normal" programming-interfaces (ITaskScheduler etc.) seem to be
based on the AT-command. Since I want to change the password, I'm now
searching for another possibility to change scheduled tasks.

Can you be a little more specific about your requirements?

Thank you

I have a typelibrary that I made for vb, and a wrapper dll.  The dll doesn't
implement remote invocation (it would amount to adding one method though),
and can be found at
http://www.mtogden.com/~tom/files/SchedulingAgentVB6.zip.  The source code
for the dll (including the idl src and the compiled typelibrary) are at
http://www.mtogden.com/~tom/files/SchedulingAgentSource.zip.  This should
give you at least some idea of what you need to do to call these methods.
To call these remotely you use the ITaskScheduler::SetTargetComputer.  Of
course you need to have remote scheduling enabled and proper permissions to
make it work.