Excluding a drive or folder isn't as straightforward as it could be, but it can be done!
This isn't click for click or word for word, but it should get you where you need to be:
- open the AVG Test Center program
- switch it to "Advanced interface" if it is not
- open the "Test manager"
- edit the "User test"
- switch to "Objects to scan"
- push the "Add folder" button
- add the path to drive you dont want to scan and push OK button to add this path to list
- right click on the new item in the "Objects to scan" list
- choose "Do not scan selected objects"
- save the test setting
- open the "Scheduled tasks"
- edit the "Test plan in basic mode"
- set the plan to use "User test" instead of "Complete test"
- save the setting by clicking "Close".