Difference between XP and Vista/7?

[Lars Brehmer]

I have a standalone that is thoroughly tested in XP and I am now  
trying in Vista and Windows 7. I never bothered with Vista before, but  
Windows 7 will surely be adopted in far greater numbers than Vista  
was, so they are obviously extremely important now.

This is a standalone that is a splashscreen with the actual program  
stacks in the package or program folder. Nothing unusual here - in  
OSX  the program stacks have always been "savable." In XP as well,  
whether the stanalone is installed or is just a program folder sitting  
on the desktop containing the .exe and other program stacks. I don't  
use any installer for OSX, just dragging the application to the  
applications folder.

When the free trial is launched for the first time, some custom  
properties which define the trial period are set in one of the stacks  
and saved. If the user buys the program, he receives an unlock code  
that also, among other things, sets some custom properties in one of  
the program stacks and saves it.

In Vista this all works as expected in the Rev IDE and also works as a  
program folder with the .exe inside on the desktop. But when I  
actually install the program and launch it from the start menu, the  
necessary custom properties for defining the the trial period and then  
the unlocking process are not saved.

I use the Inno setup compiler to create my Windows installers, and  
again, it always worked perfectly in XP. As you can see, I don't know  
a lot about Windows, I've only gotten pretty good at what it takes to  
get my standalones working in XP.

So I guess the question is this; What is different about Vista that an  
installed applications works differently than one that isn't  
installed? Why won't it save some simple custom properties once the  
standalone is actually installed? Or does the problem lie in the Inno  
setup compiler? And is it the same for Windows 7?

Any tips would be greatly appreciated!

Cheers,

Lars