Last week, I tried to reinstall Window Vista in my Dell Vostro 1510 laptop because I found it very slow and I guess there were some systems corrupted. I also found that Window Vista allow reinstall Window without deleting old data file (not choosing formatting harddisk). The system will put all files into a folder named Window.old. Later I got to manually delete those folders in Window.old because they take up a lot of disk space. Besides this, I got to reinstall all the programs again.
After that, I realized my laptop not able to dual boot as I got before this. I used to have Window and Linux dual boot system. After some searching and try out. Here are the steps.
1. Prepare a Linux bootable CD. I used CentOS, which are same to RedHat Enterprise version. Reboot laptop.
2. In the linux screen, choose F5 and type "linux rescue". It is easier step since the CD will auto-mount the Linux that I installed previously.
3. Choose Language, keyboard setting. Choose no network setup.
4. It comes to rescue environment setup. "The rescue environment will now attempt to find your Linux installation and mount it under the directory /mnt/sysimage"
5. After that, you will reach a terminal. Type: chroot /mnt/sysimage . Before this, the user name is unknow (can check by whoami command). After the chroot /mnt/sysimage command, you can recheck who is the user again by whoami command.
sudo grub [go to the grub> prompt]
find /boot/grub/stage1 [it shows the first stage system -->showing (hd0,5) for my setup
root (hd0,5) [type according to the previous result]
setup (hd0) [reinstall grub into hd0,5]
7 reboot the system. Can see the dual boot page.