Try this...
1. Use the computer's search and in the box type "Type Task Scheduler" (no quotes).
2. Right click on "Task Scheduler" in the list and then select the "Run as administrator".
3. Now go into the following folders... on the left of the window... "Microsoft", then "Windows", next "Display" and finally "Brightness".
4. Here you want to double-click on "BrightnessReset" to open its Properties.
5. Go to the "Triggers" tab and select the “At log on” trigger.
6. Next click the “Edit” and see if the "Enabled" radio button is checked
7. Now click on the radio button to clear it.
8. At last you can click "OK" on the Edit trigger page and then click "OK" on the Properties page.
base kay pareng google