Your data security and system integrity are worth far more than a few dollars saved on software. Most good disk tools are already free or have fully functional free tiers.

to avoid malware or "cracked" versions that may contain viruses. Alternatives : For users who prefer built-in Windows tools, the DiskPart command-line utility can perform similar zero-filling using the HDD Low Level Format Tool - HDDGURU

No. If the drive is not detected by BIOS, no software will fix it.