| Loading the operating system and hardware configuration |
The next step for the bootstrap program is
to locate the OS and copy it to the computer RAM. The bootstrap
loader first looks to see if the OS boot file (or boot record) is
located on a floppy drive. If not, it looks for it on the hard disk.
In some cases, if the operating system is not found on either the
floppy drive or the hard disk, the bootstrap loader will look for the
OS on the built-in CD ROM. However, the most common means of storing
the OS is on the computer hard drive. The order in which the
bootstrap program searches the OS boot up file can be changed in the
system BIOS setup. The most common order of search is as follows:
When the bootstrap finds the OS, it looks for a file called the boot record. The boot record is copied to the computer RAM and the bootstrap program then turns over the control of the boot process to the boot record. The boot record looks for files on the hard disk that help the hard disk find and locate the rest of the OS. As files are located and loaded into RAM, the boot record is no longer needed. The OS that was stored on the hard disk is now in control of the boot process. The last step of the boot process is for the OS to find hardware configuration files that are specific to the computer. If the computer has a modem or a sound card, the OS finds their configuration files (hardware drivers) and loads them.
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