[besselheim]

I had the same issue with a second hand HP laptop. However, I could still log in as administrator on the Windows install, enabling me to dump the flash memory used to store the BIOS firmware and configuration, which included the password hash. Some reverse engineering later, and I was able to brute force the hash successfully. So that could be an option if the password is not stored in battery-backed memory, and you have a bit of time on your hands to get stuck into the BIOS internals.