So many items today [b]DON'T[/b] [u]automatically save to C:\[/u] - what they do is they save to the Sub-Parent Directory that they're programmed to save into.
So, if you were to COPY (admittedly it would cause hiccups initially) your entire 'Program Files' directory to D:\ and delete C:\Program Files completely, thereafter running ALL your programs from the D:\ partition.
Come the next time an installer tried to throw something into C:\Program Files it wouldn't be able to find it. At this point one of three things would happen:
1. The installer would go off and hunt for a Program Files directory, find one on D:\ and then either put the proggy in there or ask for confirmation if you wanted that to happen.
2. The installer would report that C:\Program Files did not exist and ASK you where you wanted to put the proggy - at which point you tell it to use D:\.
3. The installer will report an error and ask if you want the C:\Program Files directory created - the system does not allow the installer to create a destination directory for an installation without user approval first. So you just click NO and point it at D:\.
From this point onward there will never be any Registry problems with program location, which you might get initially.
The only downer is that you can't throw an install at the laptop and walk away for a coffee. Mind you, as a clever person you never do that anyway - DO YOU?? ;)
It's a no-brainer!
Your only initial problem with this could be that a few program files that currently live on the C:\ partition might object to being moved, but you could always just reinstall them to D:\.
Try it, it works for me, even on a three disk tower. I've got three different 'Program Files' paths depending on what TYPE of installation it is. ;) :)
My ACER laptop doesn't seem to mind this approach either.