BEFW11S4-v4-UG-41011E KL word: definition. Firmware Upgrade 27. With the Linksys Wireless-B Broadband Router at the heart of your home network. Linksys BEFW11S4 v4 Firmware. Download Linksys BEFEW11S4v4 1.50.10 Firmware. Press the “Upgrade” button when you have filled out the required fields. To update a befw11s4_v4 to firmware 1.52.06: Get tftp.exe from: . It didn't take long to flash the upgrade. Upgrading. Upgrade the firmware to get new features or fixes.The firmware is basically a software specifically designed for this hardware. Linksys BEFW11S4 V4 Firmware 1.52.03 Update Error Solution Provided!. Upgrade failed! error when you try to update the firmware to the latest version. Linksys will not sell or rent your email address. Check out our Privacy Policy if you'd like to learn more. Who We Are. About Us; Press Room; Careers ; What We Make. Our router quicks working on a regular basis until the power is unplugged and the router reset. I am trying to upgrade the firmware in the hopes Upgrading. Upgrade the firmware to get new features or fixes.The firmware is basically a software specifically designed for this hardware. How to upgrade the firmware on a BEFW11S4. Share the Article: Note. Go to the Linksys support site. 3. I have carefully followed the directions for upgrading the firmware for my wireless router, BEFW11S4 Version 4. I keep getting the message, Upgrade Action is Not.