A long-standing common complaint is that Blender does not remember the size and placement of temporary windows, like File Browser, Preferences, Render, Drivers, Info. I am testing a patch that does just that. Open up Preferences, resize it, move it anywhere - even to a different monitor - and it will open the same way the next time you open it.
You can download builds from the following links:
This makes File Manager, Preferences, Drivers, and Info Log Windows always just remember and restore their last locations and and size.
For the Render window there is a choice. By default it will behave as it does now: auto-sizing to the render output dimensions. But go to Preferences / Interface / Editors / Temporary Editors and you can change âRender Inâ to âNew Window - Savedâ and it will load at the last size and position, regardless of render size.