On Windows 7, how does a program keep track of successive installs?

Question

I uninstalled and reinstalled a program on Windows 7 after deleting any references to it in

1. The registry (using 'find' command for 'Sneaky' and deleting keys)
2. Its original installation folder under C:\Program Files (x86)\Sneaky App
3. Its data folder under C:\Users\piper\AppData\Local\Sneaky App

After restarting the computer and reinstalling it still knows about my previous installation.

How?

Answer 1

The program may have left registry data under a key that isn't obvious. You can use Process Monitor to track what registry keys the program reads at startup.