i think the scan results option is for the pro version only...
however you can create a report file...
avast! can create and save a report file containing information about a past session. Basically, it contains the same information as in session results.
Create report file. Checking this option turns on the report file creation.
Report File Folder. Enter the path and name of the report file, e.g. C:\Reports\task_name.rpt. The folder selection can be carried out by pressing the Browse button. The default report file name is the name of the corresponding task.
Log Record For. Check the items that should be written to the report. Task start writes date and time of the task start to the report; similarly, task stop writes date and time of task stop. The description of the remaining items hard errors, soft errors, skipped files, infected files, and OK files is on the results page.
Type of file. Select the format of the report file. You can choose either a simple text file, or the newer XML format.
Note: The default report file name is task_name.rpt. The *.rpt file is actually a simple text file, so it is possible to view and modify e.g. in Notepad.