Start with a boot time scan. Move anything found to the chest. You can schedule a boottime scan from the menu on the simple user interface. (right click the "a" icon, start avast, right click on the skin)
After the boot time scan is complete and you are up and running, again do the following and post the results of the boot time scan.
Create a new restore point
You must be logged on to an administrator account
Go to Start - All Programs - Accessories - System Tools System Restore.
Click Create a restore point, and then click Next.
In the text box labeled Restore Point Description, type a name for this restore point
Remove old restore points
Disk Cleanup - Launch the Disk Cleanup tool and then select the more options tab. On this tab you will find a section for System Restore. If you press the Clean Up button for that section, Windows will delete all restore points except for the most recent one.