Just launch Acer eLock Management, enter your password and check the unlock box next to Optical Drive Devices:
After that, press Apply and restart the computer. If you no longer remember the password of Acer eLock software, right-click the Computer/My Computer icon, select Manage and open the Disk Management option. Right-click the PQService partition and select Change drive Letter and Paths. Assign a letter and you'll see the partition in Computer/My Computer. Open the partition, find the aimdrs.dat file and right click it and select Open with > Notepad. Once the file is opened, you will be able to see the password after Password= and its hint.
