If the brightness or volume keys don't work, it is almost always a missing Sony Shared Library or Vaio Event Service . Reinstall these two in Safe Mode if standard installation fails.
This is the most complex part of the VPCEH25EN setup. Sony Vaio Vpceh25en Drivers For Windows 7 64 Bit
Using generic Windows drivers or incorrect versions can lead to: If the brightness or volume keys don't work,
Without these, you are offline.
Always store a backup of your working drivers on an external USB drive or cloud storage. If you reinstall Windows again in the future, you’ll save hours of searching. For enthusiasts, consider also updating your hard drive to a SATA SSD and maxing out the RAM to 8GB—but to enable AHCI mode. Sony Vaio Vpceh25en Drivers For Windows 7 64 Bit