Correct.

Even the admin does not have "admin" rights all the time.

If you want to write to "c:\program files\MyGame\My Game data.txt" then the user will either get a message saying your program is about to access this file and requires access. Or it will not in fact write to that file but in

c:\users\your user name\...\My Game data.txt which gets kind of confusing when you are trying to work out why the data hasn't been updated.

I don't have Vista installed anymore. So I can't elaborate. All I know for sure is that I changed my project so that any files that need to be changed (e.g. database file) are stored in "my Documents\My Project" folder

I had problems with registry keys in local machine because they contained copy protection information. If a user entered the unlock codes they weren't being written to local machine anymore but to "local user" registry key. That means that information was not available to other users of the computer. So that for other users on the system the product had not infact been unlocked at all.

That was a right confusing mess.