Select HDD games and if the HDD is unformatted you will be asked to format it. Once the format is done, you will be able to install and play games.
In order not to harm the laser of the console, especially if you are an owner of V9 or V10 (see "romeo" mod), by installing games directly from the PS2 drive, you can connect the PS2 HDD on the PC and with an easy to use program called WinHIIP
you are able to install games on the HDD.
Try to install some games and check if they boot. If you see a "black screen" and the game is not loading, just change the compatibility mode.Compatibility modes solve most of the games that don't work. These modes fix the most common issues, ensuring that most of the games will work. You can change the compatibility mode either in the WinHIIP
or in the ToxicOS.
Note that most of the games do not require a selected "compatibility mode". So change the mode only in games that they do not work. If you try the 3 different modes and the game is still not loading, then you are out of luck, and it means that the game is not supported by the ToxicOS. In that case you have to use your original PS2 disc or a DVD/CD back-up.
Finally for those who have selected to boot their console with the ToxicOS and they want to boot on the default PS2 menu, they can just press the triangle when the PS2 is booting.