The problem with finding proper flashing utility is that there are multiple ways a BIOS flash chip could be connected to the motherboard in. Usually it is using interfaces like LPC/FWH/SPI/etc. Then there are flash chips from different chip manufacturers, many of which while supposed to be standard are in fact require slightly different flashing procedures. Then there are different BIOS Vendors which have different formats and therefore different flashing utilities which have to account for the format differences.
If you are still eager to screw up your motherboard - start with opening your BIOS image with a hex editor and look for the BIOS vendor patterns like "ami", "award", "phoenix" - then look for the flashing utility from the vendor whose name you found. You may have to try multiple versions before you find one recognizing the flash chip on your motherboard.
I edited your question to include the system's manufacturer/model name and OEM of the motherboard. Packard Bell is no help and Gigabyte does not support the OEM boards. At least Gigabyte provided the generic (Award/Phoenix) BIOS for the board. It did not come with any flashing utility which might mean that there is a flashing facility in the BIOS itself (which could be missing from the BIOS that Packard Bell put in their systems)