A confirmed bug in Ubuntu 13.10 prevents users from switching layouts using combinations like Alt+Shift, Caps Lock, Ctrl+Shift etc.
The bug affects many people, its importance is set to "High", so we may expect that an official fix will be released soon. You can subscribe to notifications about this bug on launchpad.net, so that you receive an email when it's done.
Currently, a patch aimed at resolving this issue is being tested. By now it seems to work for most users, though certain problems remain. To install the patch, use the following commands:
sudo add-apt-repository ppa:attente/modifier-only-input-switch
sudo apt-get update
sudo apt-get upgrade
A system reboot was needed in my case to make it work (simple log out and log in may be sufficient).
Note: Originally, the patch was located at ppa:attente/1218322. If you have previously installed it from there, you can first purge it as follows
sudo ppa-purge ppa:attente/1218322
and then execute the three commands above.
Alternatively, you may consider using a combination containing a non-modifier key (a letter, digit, space): try, for instance, Alt+Shift+Space (this will work without installing any patches).
Note that the keyboard shortcuts for switching layouts still do not work on lock screen (it is a separate bug). If you are stuck on lock screen and unable to enter the password because of the wrong layout, simply click the language indicator icon on the right of the password field.
Best Answer
I'm very sorry to say but you want Ubuntu to be Windows, which is not going to happen tomorrow... :-(
Ubuntu is based on Linux, and although it has "windows" than can be dragged around a "desktop" and that it adheres to the CUA like Windows, it's just not the same thing! Asking for something and ruling out all possible answers is just going to leave you with an answer like this:
Sorry to be the harbinger of bad news, but what you're asking for is impossible...