Changing Win 7 DPI settings without restarting or logging off

Is there anyway to change the dpi / magnification settings in Windows 7 without having to log off and back on or restart the machine?

I'm looking at a Studio 1557 laptop as a desktop replacement with a 1080p (1920 X 1080) screen which I think will make the text and icons quite small. I can easily change the DPI to 120 (125%) or 144 (150%) and make everything readable which is great however when it's at a desk it's going to be connected to two 20 inch plus monitors and these require the normal 96dpi (100%).

The problem is the machine will be frequently connected and disconnected and having to close and reopen all applications to restart the machine properly is a real pain.

Windows XP used to warn you about having to restart but if you didn't things were still resized. With Win 7 nothing happens until you do.

Does anyone have any suggestions?

I'd rather have a bit more definition than the 720p offers and as mentioned in another thread ideally I'd like a resolution in between but this isn't possible.

As a side note has anyone bought the 1080p version and wished they'd bought the 720p one instead or vice versa?

 

More definition? Try 16801050 or 1680x945.

 

I didn't want to run a non native resolution for the lcd if possible as it doesn't give the best results compared to the screen scaling by changing the dpi gives better results but it may end up being one of my options.

 

The 900p option (1600x900) sounds like a good idea for you.

 

I've been looking into the 900p option which sounds absolutely perfect and I'd love one, unfortunately it's not available as an option in the UK (where I'm based) or from what I can see Europe either.

I noticed they have it in the US and have even tried calling the UK CS to see if they can fit one but apparently not and they know nothing about it coming to the UK soon either.