Click the Download button.
Save the file to your computer and note the directory where the file is saved. A firmware update installed over the LAN, GPIB, or USB interface is a file with a .upd extension.
Unzip the file to access the .upd file. For updates using a front panel USB drive, the utility extracts the required files from the (unzipped) .upd file.

From the utility directory or Start menu, start the utility (FWUpdate.exe). The utility will prompt you for the location of the .upd file. Follow the additional prompts to complete the installation. The update may take several seconds to complete and will reboot the instrument. After the update is complete, exit the utility.

It is not necessary to re-calibrate the instrument following a firmware-update; however, the instrument may need to be re-secured if it was unsecured to perform the update.

* NOTICE: Downgrading the 3446xA and 34470A Firmware
Before downgrading to a ‘Previous’ firmware revision, note the firmware revision currently installed (Shift - Help – About).
Firmware revision A.03.01-02.40 and below can be downgraded to any previous (posted) revision.
Firmware revision A.03.01-03.15 cannot be downgraded, and revisions above that can only be downgraded to A.03.01-03.15. Firmware downgrade to version below A.03.01-03.15 will cause unit to lock up/hang.

* NOTICE: Upgrading the 34460A and 34461A with firmware revision 1.xx to revision 3.0 or greater
34460A and 34461A DMMs with firmware revision 1.08, 1.09, or 1.10 currently installed must first be upgraded to revision 2.17 (see the ‘Previous Versions’ tab), and then upgraded to revision 3.0 or greater. Upgrades to 3.0 or greater (from 1.xx) cannot be done directly. If attempted, the DMM can be recovered by updating the firmware (to 2.17) from the front panel USB port. Select ‘Front Panel’ on the Firmware Update Utility to create the appropriate folder on a USB thumb drive.