I have the following problem using matlab on Windows 7.

When I double-click a .mat file matlab starts and loads the double-clicked file. Double-Clicking further .mat files opens them also in matlab. So far so good...

On the ohter hand, when I start matlab manually by clicking its Icon on the desktop, I get an "User Account Control" alert asking me if I "want to allow the following program from an unkown publisher to make changes to this computer".

The problem is that a double-click on a .mat file opens another instance of matlab. The running matlab is for some reason not recognized. Does anyone know how to fix this behaviour?