How do I install the Quartus II software when the installation wizard only displays the "update", "uninstall", or "repair" options?

Description You may run into this problem if you had previously installed the Quartus II software, but did not do a proper uninstall. As a result, there may be some remnants in the registry that lead the install script to believe that the Quartus II software still exists. Therefore, it only displays the options to "update", "uninstall", and "repair", and will not allow you to initiate a fresh install. Before you can troubleshoot this issue, please download the following Microsoft utilities:

1. regclean
2. powertoys

After obtaining the utilities, you can fix this problem by manually deleting all Quartus II directories and then cleaning your registry as follows:

1. Delete all Quartus program files and directories.
2. Create a folder for "regclean", and move the downloaded regclean file into the folder.
3. Install regclean, and run regclean.exe. Click on 'Fix Errors'. Once the program has completed, click 'Finish'.
4. Reboot.
5. Create a folder for powertoys, move downloaded powertoys file into folder.
6. Find tweakui.inf, right click, and select 'Install'. Close the pop-up window with readme documentation.
7. Enter control panel and double click on the tweakui control panel icon.
8. Select Add/Remove tab and find the Altera Quartus entry in the menu window. Select the Quartus entry and click on 'Remove' and then 'OK'.
9. Reboot.
10. Reinstall the Quartus software.

Note: These types of problems may vary from user to user because they are caused by problems in the Windows registry, which is accessed by most applicationsespecially during installation and uninstallation. Consult your corporate IT staff for additional help in fixing problems with your Windows environment. For problems and/or questions with these utilities, please contact Microsoft directly.