Problems installing or uninstalling
StoreTender's installation package creates an entry in the Add/Remove Programs, found in the Windows Control Panel. The installation is completed using Windows Installer. At times there could be problems installing or uninstalling, where Windows advises that it cannot continue because another version already exists.
If you are unable to uninstall an old version so you can install a new one, you might need to run the Microsoft Fix-It tool related to the Windows Installer.
The tool can be downloaded from this Microsoft web page: https://support.microsoft.com/en-in/help/17588/fix-problems-that-block-programs-from-being-installed-or-removed
Navigate to the above page by clicking on the link. Follow the instructions to run the tool.