How to execute program before the uninstallation starts?

Question

Can InnoSetup execute a program before the uninstallation starts? My program creates some registry values. I have an executable that can remove those registry values and my

Answer 1

See the documentation on Setup Script Sections, particularly the UninstallRun one at the bottom of the tree:

[UninstallRun]
Filename: "{app}\INIT.EXE"; Parameters: "/x"

If you need to do something more complex, you can also do it in code using the Pascal scripting functionality in InnoSetup. See UninstallCodeExample1.iss' in theInnoSetup 5\Examples` folder.