The HP Vectra VL420 DT is a business-oriented computer featuring an Intel Pentium 4 processor and easy-to-service design. As with other PCs, the Vectra VL420 DT motherboard uses the Basic Input/Output System, or BIOS, for basic hardware management. The BIOS normally performs as it should, but sometimes it is necessary to clear the BIOS when troubleshooting a technical issue. Learn how to clear the BIOS on the Vectra VL420 DT to reset the system settings and fix technical problems.
Turn off the HP Vectra VL420 DT and unplug all cables from the unit.
Remove the computer case cover to access the system components. Place the case right-side down to expose the cover latch. Pull the latch up to release the cover.
Touch an unpainted metal portion of the case to discharge static electricity from your body. Use a small flathead screwdriver to gently pry out the CMOS battery. Look for this nickel-shaped battery next to the white PCI slots in the lower-left corner of the computer.
Replace the CMOS battery after several minutes. This deprives the motherboard of electricity and clears the BIOS. Put the system cover back on and plug in the HP Vectra.