Last week, I ran into trouble while trying to install Windows XP (as a dual boot) to my PC that already has Windows Vista. If you have never done it but are thinking of doing, then BE VERY CAREFUL!!! There are many things you need to be aware with dualbooting with Vista. After copying files from the CD during installation process, it restarted automatically to boot from XP. But it can't boot any more!!! Neither from Vista nor from XP. It says something like operating system is missing.
After googling for a while, I found out that Vista uses a totally different boot process from XP. Therefore, it must have been messed up by XP installation. I couldn't load boot menu to try safe mode or last known configuration either. Because it's OEM version, I didn't get any install DVD or recovery disc.
Finally I found and downloaded Windows Vista Recovery Disc thanks to NeoSmart. You can download the torrents from the following links. You need to have a torrent software to download them. You only need one depending on the version you have.
Windows Vista 32-Bit (x86) Recovery Disc Torrent
Windows Vista 64-Bit (x64) Recovery Disc Torrent.
After downloading the ISO file, you need to burn it to a CD and boot from the CD (press F12 during power up). I have taken some screenshots for step by step procedure. You can use Vista installation DVD too if you have one.
Now take the Recovery CD out of the drive and restart the pc. You should be able to boot from Vista this time.