GRUB uses a simple description

In more than one operating system installed, sometimes makes the GRUB is missing, as I reload XP, XP will give GRUB from MBR, clear.

In the process of upgrading LINUX GRUB installation failed or enter console status. GRUB features many, for general users mainly want to know the ROOT, SETUP, INSTALL, ROOTNOVERIFY, CHAINLOADER, GRUB.CONF, for different file system STAGE1, STAGE2 files. GRUB won't download, what to say, generally do not need to download and install disk contains. ROOT use format is: ROOT (HDX, Y) where x is from 0-N, Y. The first hard drive, first partition is (HD0, 0), the first hard drive, second partition is (HD0, 1); the second hard drive, first partition is (HD1, 0), the first hard drive, second partition is (HD1, 1); and so on, you can know the ROOT of usage. ROOT is GRUB recognizes the hard drive and file formats of commands that tells GRUB next to get there and find GRUB configuration file to start the core, or start the IMG file. SETUP and INSTALL GRUB is installed to a specified location, such as: MBR, specific HELP file you can see, there is nothing special about it. STAGE1 and STAGE2 for different file system, you can to GRUB bag or find/USR/SHARE/GRUB directory, copy into GRUB directory. GRUB.CONF format: default = 0 timeout = 10 splashimage = (hd1, 2)/boot/grub/splash.xpm.gz titleWindowsXP rootnoverify (hd0, 0) chainloader + 1 titleRedat9 root (hd0, 1) kernel/boot/vmlinuz-2.4.20-8roroot = LABEL =/boot/initrd/initrd-2.4.20-8.img titleMandrake9.1 kernel (hd1, 4)/boot/vmlinuzroot =/dev/hdb5quietdevfs = mountacpi = offvga = 788 initrd (hd1, 4)/boot/initrd.img default = X as the default boot system, 0 is the first system, and so on. Timeout = X to the grub menu over time, in seconds, for the title XXX titleXXX, that is, you have to boot the operating system name, you can modify the rootnoverify (hd0, 0) tell GNUGRUB you have where WidnowsC disc, but do not try to mount it (' noverify ', options). Chainloader + 1 tell GNUGRUB do not try to load Windows itself (its not complete), but to start the process over to the c drive, where the first sector that contains the original DOS/Windows boot process.