windows和linux双系统，设置默认启动项在终端里输入：sudogedit/boot/grub/grub.cfg先装windows而后装linux系统，默认启动项会非常多，执行上面的命令后，会打开一个文档，里面代码如下：---------------------------------------------------------------------------------------------------------------(这些小横线是我自己加的)##DONOTEDITTHISFILE##Itisautomaticallygeneratedby/usr/sbin/grub-mkconfigusingtemplates#from/etc/grub.dandsettingsfrom/etc/default/grub####BEGIN/etc/grub.d/00_header###if[-s$prefix/grubenv];thenload_envfisetdefault="8"if[${prev_saved_entry}];thensetsaved_entry=${prev_saved_entry}save_envsaved_entrysetprev_saved_entry=save_envprev_saved_entrysetboot_once=truefifunctionsavedefault{if[-z${boot_once}];thensaved_entry=${chosen}save_envsaved_entryfi}functionrecordfail{setrecordfail=1if[-n${have_grubenv}];thenif[-z${boot_once}];thensave_envrecordfail;fi;fi}insmodext2setroot='(hd0,9)'search--no-floppy--fs-uuid--setfd9c0f6c-5c20-4d95-b3f4-eebca82bea0fifloadfont/usr/share/grub/unicode.pf2;thensetgfxmode=640x480insmodgfxterminsmodvbeifterminal_outputgfxterm;thentrue;else#Forbackwardcompatibilitywithversionsofterminal.modthatdon't#understandterminal_outputterminalgfxtermfifiinsmodext2setroot='(hd0,9)'search--no-floppy--fs-uuid--setfd9c0f6c-5c20-4d95-b3f4-eebca82bea0fsetlocale_dir=($root)/boot/grub/localesetlang=zhinsmodgettextif[${recordfail}=1];thensettimeout=-1elsesettimeout=10fi###END/etc/grub.d/00_header######BEGIN/etc/grub.d/05_debian_theme###setmenu_color_normal=white/blacksetmenu_color_highlight=black/light-gray###END/etc/grub.d/05_debian_theme######BEGIN/etc/grub.d/10_linux###menuentry'Ubuntu,withLinux2.6.32-31-generic'--classubuntu--classgnu-linux--classgnu--classos{recordfailinsmodext2setroot='(hd0,9)'search--no-floppy--fs-uuid--setfd9c0f6c-5c20-4d95-b3f4-eebca82bea0flinux/boot/vmlinuz-2.6.32-31-genericroot=UUID=fd9c0f6c-5c20-4d95-b3f4-eebca82bea0froquietsplashinitrd/boot/initrd.img-2.6.32-31-generic}menuentry'Ubuntu,withLinux2.6.32-31-generic(recoverymode)'--classubuntu--classgnu-linux--classgnu--classos{recordfailinsmodext2setroot