For a single time..
Open all the file.. in same excel instance..
Arrange the file's position if required..
In View menu.. Save Workspace.. and give it a desired name..
Next time.. just simply opne the Workspace.. it will open all the file with same setted position..
PS: Is really VBA required.. !!
how to make sure macros in each file will run automatically once open the workspace ?
Simple.. by testing..
No.. its not a problem with Workspace.. its problem with your setting..
All files need to "Enable content" upon open. So you have to click each "Enable Option" option..
or
Go to excel Option > Trust Center > Trusted Location > Set the desired folder (in your case c:\temp\) as a trusted location it will not ask to "enable macro" for those files..