Task running right after another

[minor]

This is what I would like to do, ideally:

Have one task start at a set time, then have a bunch of
other tasks run right after the one previous to them
finishes.

What would be the most efficient way to do this? I'd like
to have multiple tasks, not have to combine them all into
one, as there are roughly 100.

Each task extracts information from a quickbooks file into
a database.

[Oleg]

You may simply create some task which launch other tasks with waiting for finish.

For example:
Start task "task1" and wait for finish
Start task "task2" and wait for finish
Start task "task3" and wait for finish
and etc

See the action "Start task" in "Task commands" group
Thus you may garantee that your tasks will be started in necessary sequence and each task will start when previous task will be done.

[minor]

Thank you!
One more question:
When the data is extracted from QuickBooks, a dialogue pops up. It either says "completed after X seconds" or has an error message that the data couldn't be extracted for a reason. If the data can't be extracted, I would like some sort of notification, even just writing a line into a text file with the date/time. This seems easily solved by being able to identify the window, and if it were incorrect, adding a line to a text file, the closing the error window and continuing with the next task.
This is what I have set up so far- it has a 'wait for window,' however, I have a hard time distinguishing between the confirmation window and an error window, as both their captions are "Microsoft Access" and they have the same window class. Is there any way to base identification off the text contained in the window?
 
 
 

[minor]

Also, curious if there's a faster way to change directory
in multiple tasks without having to edit each individual
one- ie change "\Microsoft Office\Office\MSACCESS.exe" to
"\Microsoft Office\Office11\MSACCESS.exe" in a couple
hundred tasks.