If you install the program,

Hello Taecheol, 
We will certainly look into it and help you.
Please mention the name of the AVG programs in which you're facing this installation issue.
For better clarity, please share the screenshot of the error message which you get while installing the AVG program.
If needed, please find a quick guide on how to take a screenshot here.
If the program is already installed and unable to access it, I'd recommend you to repair the concerned AVG program, restart your computer and check the status.
For repair steps, please follow the steps mentioned in the below article,
Repairing AVG AntiVirus
Thank you.

Hello Taecheol, 
We will certainly look into it and help you.
Please mention the name of the AVG programs in which you're facing this installation issue.
For better clarity, please share the screenshot of the error message which you get while installing the AVG program.
If needed, please find a quick guide on how to take a screenshot here.
If the program is already installed and unable to access it, I'd recommend you to repair the concerned AVG program, restart your computer and check the status.
For repair steps, please follow the steps mentioned in the below article,
Repairing AVG AntiVirus
Thank you.

If you install the program,
Please contact your system administrator.
There's an error message box.