Fn is not work, so how to mimimize brightness of M115-s3154 toshiba laptop?

SOURCE: i have a toshiba satellite m115 s3154. i cant find

• Hi, first, go to the “Control Panel” select and open. “Next, click to open the “Device Manager, or Hardware & Sound.” Select, “view, or update" Drivers; click on to open the Disk Drive icon. In the Device Status, check to see if, “working properly” If so do the following; Click on the Driver button,” once the window open “check (two) areas. Rollback Driver, “if this area is not “Grayed-out; rollback drivers, “Apply, and click “OK.” Restart the computer.” The second area is the “Update Driver,” Click to update! Apply and click OK. Final step is to “restart the "computer” Important sometimes the ‘Drivers” can be “inactive mode” not disabled, nor recognized), just not functioning correctly. In a final attempt to get, the drivers up and running, take these steps: Click on the “Update Drivers” choose (“Browse my computer for driver software”), select to open. “Next, select: (“Let me pick from a list…”) ‘once the next ‘window appear, click to “highlight” the Driver, and click the Next (tab), follow all instructions thereafter; restart the computer. “Helpful Ratings Feedback is appreciated, thanks .”
  

SOURCE: toshiba m115-s3154 laptop won't power on

if its not the battery or the power adapter then it could be something to do with bios settings or corrupt master bot records

SOURCE: SCREEN PROBLEMS Toshiba Satellite M115 S3154.

maybe it has to do with your power settings or screen view properties which can generally be accessed by rgiht clicking on the desktop then properties or else nvidia if u have that.