刚安装了双系统，分别是windows7（先）和Ubuntu10.04（后）（非wubi安装),. 默认是Linux启动,通过下面的操作可把windows7改为默认启动系统
启动ubuntu后，在终端中输入：
先备份 sudo cp /boot/grub/grub.cfg /boot/grub/grub.cfg.backup
修改启动列表：sudo gedit /boot/grub/grub.cfg(注意不是sudo gedit /boot/grub/menu.lst,
貌似9.10就改为了grub.cfg）
然后找到default 0然后往下看，找你想默认启动的操作系统！修改default 后面的数字，0对应第一个，1对应第二个，依次往下！以下是我的grub.cfg默认是ubuntu！把0改为4就可以了！(升级内核之后数字酌情修改）
## DO NOT EDIT THIS FILE## It is automatically generated by /usr/sbin/grub-mkconfig using templates# from /etc/grub.d and settings from /etc/default/grub#### BEGIN /etc/grub.d/00_header ### if [ -s $prefix/grubenv ]; thenload_envfiset default=”0″if [ ${prev_saved_entry} ]; thenset saved_entry=${prev_saved_entry}save_env saved_entryset prev_saved_entry=save_env prev_saved_entryset boot_once=truefifunction savedefault { if [ -z ${boot_once} ]; thensaved_entry=${chosen}save_env saved_entryfi}function recordfail { set recordfail=1if [ -n ${have_grubenv} ]; then if [ -z ${boot_once} ]; then save_env recordfail; fi; fi}insmod ext2set root='(hd0,3)’search –no-floppy –fs-uuid –set 0ee185d8-a603-4309-97b7-6440643becb7if loadfont /usr/share/grub/unicode.pf2 ; thenset gfxmode=640x480insmod gfxterminsmod vbeif terminal_output gfxterm ; then true ; else# For backward compatibility with versions of terminal.mod that don’t# understand terminal_outputterminal gfxtermfifiinsmod ext2set root='(hd0,3)’search –no-floppy –fs-uuid –set 0ee185d8-a603-4309-97b7-6440643becb7set locale_dir=($root)/boot/grub/localeset lang=zhinsmod gettextif [ ${recordfail} = 1 ]; thenset timeout=-1elseset timeout=10fi### END /etc/grub.d/00_header ###### BEGIN /etc/grub.d/05_debian_theme ### set menu_color_normal=white/blackset menu_color_highlight=black/light-gray### END /etc/grub.d/05_debian_theme ###
### BEGIN /etc/grub.d/10_linux ### menuentry ‘Ubuntu，Linux 2.6.32-21-generic’ –class ubuntu –class gnu-linux –class gnu –class os {recordfailinsmod ext2set root='(hd0,3)’search –no-floppy –fs-uuid –set 0ee185d8-a603-4309-97b7-6440643becb7linux /boot/vmlinuz-2.6.32-21-generic root=UUID=0ee185d8-a603-4309-97b7-6440643becb7 ro quiet splashinitrd /boot/initrd.img-2.6.32-21-generic}menuentry ‘Ubuntu，Linux 2.6.32-21-generic (恢复模式)’ –class ubuntu –class gnu-linux –class gnu –class os {recordfailinsmod ext2set root='(hd0,3)’search –no-floppy –fs-uuid –set 0ee185d8-a603-4309-97b7-6440643becb7echo ‘载入 Linux …’linux /boot/vmlinuz-2.6.32-21-generic root=UUID=0ee185d8-a603-4309-97b7-6440643becb7 ro single echo ‘载入引导虚拟磁盘 …’initrd /boot/initrd.img-2.6.32-21-generic}### END /etc/grub.d/10_linux ###### BEGIN /etc/grub.d/20_memtest86+ ### menuentry “Memory test (memtest86+)” {insmod ext2set root='(hd0,3)’search –no-floppy –fs-uuid –set 0ee185d8-a603-4309-97b7-6440643becb7linux16 /boot/memtest86+.bin}menuentry “Memory test (memtest86+, serial console 115200)” {insmod ext2set root='(hd0,3)’search –no-floppy –fs-uuid –set 0ee185d8-a603-4309-97b7-6440643becb7linux16 /boot/memtest86+.bin console=ttyS0,115200n8}### END /etc/grub.d/20_memtest86+ ###### BEGIN /etc/grub.d/30_os-prober ### menuentry “Windows 7 (loader) (on /dev/sda1)” {insmod ntfsset root='(hd0,1)’search –no-floppy –fs-uuid –set 6e40b6ff40b6ccd9chainloader +1}### END /etc/grub.d/30_os-prober ###### BEGIN /etc/grub.d/40_custom ### # This file provides an easy way to add custom menu entries. Simply type the# menu entries you want to add after this comment. Be careful not to change# the ‘exec tail’ line above.### END /etc/grub.d/40_custom ###
→→此处分割←←
上面的自己修改default后面的数字。！··
如果你觉得这样不方便到话，我建议你把win7的那一项剪切到ubuntu前面
也就是这个样子，这样既美观又方便（不用修改default后面的数字）。
## DO NOT EDIT THIS FILE## It is automatically generated by /usr/sbin/grub-mkconfig using templates# from /etc/grub.d and settings from /etc/default/grub#### BEGIN /etc/grub.d/00_header ###if [ -s $prefix/grubenv ]; thenload_envfiset default=”0″if [ ${prev_saved_entry} ]; thenset saved_entry=${prev_saved_entry}save_env saved_entryset prev_saved_entry=save_env prev_saved_entryset boot_once=truefifunction savedefault {if [ -z ${boot_once} ]; thensaved_entry=${chosen}save_env saved_entryfi}function recordfail {set recordfail=1if [ -n ${have_grubenv} ]; then if [ -z ${boot_once} ]; then save_env recordfail; fi; fi}insmod ext2set root='(hd0,3)’search –no-floppy –fs-uuid –set 0ee185d8-a603-4309-97b7-6440643becb7if loadfont /usr/share/grub/unicode.pf2 ; thenset gfxmode=640x480insmod gfxterminsmod vbeif terminal_output gfxterm ; then true ; else# For backward compatibility with versions of terminal.mod that don’t# understand terminal_outputterminal gfxtermfifiinsmod ext2set root='(hd0,3)’search –no-floppy –fs-uuid –set 0ee185d8-a603-4309-97b7-6440643becb7set locale_dir=($root)/boot/grub/localeset lang=zhinsmod gettextif [ ${recordfail} = 1 ]; thenset timeout=-1elseset timeout=10fi### END /etc/grub.d/00_header ###### BEGIN /etc/grub.d/05_debian_theme ###set menu_color_normal=white/blackset menu_color_highlight=black/light-gray### END /etc/grub.d/05_debian_theme ###### BEGIN /etc/grub.d/30_os-prober ###menuentry “Windows 7 (loader) (on /dev/sda1)” {insmod ntfsset root='(hd0,1)’search –no-floppy –fs-uuid –set 6e40b6ff40b6ccd9chainloader +1}### END /etc/grub.d/30_os-prober ###### BEGIN /etc/grub.d/10_linux ###menuentry ‘Ubuntu，，Linux 2.6.32-21-generic’ –class ubuntu –class gnu-linux –class gnu –class os {recordfailinsmod ext2set root='(hd0,3)’search –no-floppy –fs-uuid –set 0ee185d8-a603-4309-97b7-6440643becb7linux /boot/vmlinuz-2.6.32-21-generic root=UUID=0ee185d8-a603-4309-97b7-6440643becb7 ro quiet splashinitrd /boot/initrd.img-2.6.32-21-generic}menuentry ‘Ubuntu，Linux 2.6.32-21-generic (恢复模式)’ –class ubuntu –class gnu-linux –class gnu –class os {recordfailinsmod ext2set root='(hd0,3)’search –no-floppy –fs-uuid –set 0ee185d8-a603-4309-97b7-6440643becb7echo ‘载入 Linux …’linux /boot/vmlinuz-2.6.32-21-generic root=UUID=0ee185d8-a603-4309-97b7-6440643becb7 ro single echo ‘载入引导虚拟磁盘 …’initrd /boot/initrd.img-2.6.32-21-generic}### END /etc/grub.d/10_linux ###### BEGIN /etc/grub.d/20_memtest86+ ###menuentry “Memory test (memtest86+)” {insmod ext2set root='(hd0,3)’search –no-floppy –fs-uuid –set 0ee185d8-a603-4309-97b7-6440643becb7linux16 /boot/memtest86+.bin}menuentry “Memory test (memtest86+, serial console 115200)” {insmod ext2set root='(hd0,3)’search –no-floppy –fs-uuid –set 0ee185d8-a603-4309-97b7-6440643becb7linux16 /boot/memtest86+.bin console=ttyS0,115200n8}### END /etc/grub.d/20_memtest86+ ###### BEGIN /etc/grub.d/40_custom #### This file provides an easy way to add custom menu entries. Simply type the# menu entries you want to add after this comment. Be careful not to change# the ‘exec tail’ line above.### END /etc/grub.d/40_custom ###
每次更新内核，你都要重新修改这个启动项
你能给的也只有这么多，在这个狭小的圈子里，
