NOTE: If you wish to install NetBSD on your whole disk, i.e. you do not want DOS or any other operating system to reside on your hard disk, you can skip this section and go on to the section that describes installation, below. If you're upgrading your system from a previous release of NetBSD, you shouldn't have proceeded directly to the section about upgrading; you need none of the information presented here. First and foremost, before beginning the installation process, MAKE SURE YOU HAVE A RELIABLE BACKUP of any data on your hard disk that you wish to keep. Repartitioning your hard disk is an excellent way to destroy important data. Second, if you are using a disk controller which supports disk geometry translation, be sure to use the same parameters for NetBSD as for DOS or the other operating systems installed on your disk. If you do not, it will be much harder to make NetBSD properly coexist with them. Utilities exist which will print out the disk geometry which DOS sees; some versions of DOS "fdisk" also do this. If you have an "EIDE" hard disk, DOS and NetBSD probably won't see the same geometry, and you must be careful to find out the DOS geometry and tell NetBSD about it during the installation. Third (but related to the second point above), if you are using a hard disk with more sectors than DOS or your controller's BIOS supports without some kind of software translation utility or other kludge, you MUST BE SURE that all partitions which you want to boot from must start below cylinder 1024 by the BIOS's idea of the disk, and that all DOS partitions MUST EXIST ENTIRELY BELOW cylinder 1024, or you will either not be able to boot NetBSD, not be able to boot DOS, or you may experience data loss or filesystem corruption. Be sure you aren't using geometry translation that you don't know about, but that the DOS "fdisk" program does! Fourth, use the DOS "fdisk" program or another partition editor to repartition your hard disk. Create a partition of at least 40M in size (preferably much larger), and note its starting offset and its length (preferably in units of disk sectors or cylinders). You will need that information when installing NetBSD (and if the offset and length are not in those units, you will have to convert them). Once you have created the new NetBSD partition, mark it as having a partition type of 0xA5 (165, in decimal). If you used "fdisk" to partition your disk, you will probably have to use a different partition editor to mark the partition with the correct type. Finally, do whatever is necessary to restore order to the partition you took space away from. If it was a DOS partition, you probably will need to use "format" to create a new file system on it, and then restore your important files from your backups. Other operating systems will have different needs; most will need to reformat the partition, and if it was their "main" partition, will probably need to be reinstalled. Your hard disk is now prepared to have NetBSD installed on it, and you should proceed with the installation instructions.