Код:
procedure CurStepChanged(CurStep: TSetupStep);
begin
if CurStep = ssInstall then
DelTree(ExpandConstant('{userappdata}\TEST'), True, True, True);
If not IsWin64 then
RegDeleteKeyIncludingSubkeys(HKLM, 'SOFTWARE\TEST');
If IsWin64 then
RegDeleteKeyIncludingSubkeys(HKLM64, 'SOFTWARE\TEST');
end;