v. 10 and 11- no chance to install the new version 11

Hello Steffen!

Welcome to our Forum, we're glad you joined us! I completely understand your concern, and will be glad to assist you with the issue.

Unfortunately due to the lack of information it is difficult to identify the exact cause of the issue, but I assume that the registry was messed up, since Acronis Disk Director Suite 10.0 doesn't support Windows 7. We cannot guarantee stability of the system on installation and uninstallation of the product, but let's try to remove it and improve the situation. Please follow these steps: 

1. Deactivate OS Selector manually (if any)
2. Run Clean-Up utility in order to remove all the traces that could've been left
3. Reboot the machine
4. Run installation file of Acronis Disk Director Suite 11

This should help to resolve the issue. I would appreciate if you could kindly keep us posted regarding this question - this will allow us to provide you with further assistance if required.

Should you need anything else or have any further questions - feel free to contact us at your earliest convenience, we will be happy to help you!

Thank you for cooperation! I will be looking forward for news from you.