Be carefull with LLF!
This is job only for advanced users!
Not recomended for end-users.
LLF is not included in new BIOS`s function (Award and Ami). You can make it with Quantum Disk Manager ver.9.52 in option Utilities. It has 2 function-zero filling drive and LLF. After do this, you need make new partition table and format all partitions. All old data will be destroyed. Follow instructions on the screen and read careful all warnings from the software. Download DM 9.52 for DOS from http://service.quantum.com/softsourse/disk_docs/dm2000.htm