Hello Gerhard,
I am sorry to hear about this. Do you encounter any error while trying to install AVG PC TuneUp? If so, please share the screenshot of the error message to assist further.
Gerhard, If applicable… For your info, just in case that you are unaware, you can post the screenshot here in your topic. Click on 'Answer' & then click on the 'Image' [mountain symbol] & follow the instructions.
AVG Guru