I got very tired of having to select "View..Scientific" every time I started the calculator (calc.exe).
It turns out that if you are a non-administrative user (you're not doing daily work as an admin, are you?), then it doesn't save the last-used state.
To make the calculator start in scientific mode every time, edit C:\WINDOWS\win.ini, and add this:
[SciCalc] layout=0
If you're using Vista, you can set it in the registry
