Disable your antivirus temporarily (false positives are common for uninstaller tools due to their deep system access). Run the setup as Administrator.
One of the "Full" exclusive features is the installation monitor. Before installing new software, activate the monitor. Smarty will take a system snapshot and, upon uninstallation, revert every single change made by that installer. Smarty Uninstaller 4.10.0 Full
Because Smarty Uninstaller is discontinued and its original digital signatures expired, modern antivirus engines often flag the cracked SmartyUninstaller.exe as: Smarty Uninstaller 4.10.0 Full