|You didn't need to buy software to "scrub the drive". Everything is done with the XP disc. Double check the boot order settings in the BIOS. Make sure the CD/DVD drive is listed before the HDD. If it's not, change the settings, save & exit. Then boot off the XP disc, delete all current partitioning, create at least 2 new partitions (one for Windows, one for data storage), format using NTFS (full), then install XP. Make sure you have all the necessary drivers ready in advance (chipset, video, sound, network, etc). If your disc doesn't include SP3, download it from the Miscrosoft website & install it right away. And install one of the free lightweight anti-virus programs such as AVG, AVAST, or Microsoft Security Essentials. Do NOT install McAfee, Norton, TrendMicro or any other of the bloated AV hogwares.|
If you have a SATA HDD, there are numerous other steps that will need to be taken because the HDD will NOT be recognized.
BTW, clearing the password is very simple, maybe you should try that 1st?