I am a new user of ubuntu and have practically no knowledge of how ubuntu works. A week ago i installed ubuntu on a pen drive (windows was corrupted) and since then i have been booting ubuntu via pen drive. Now, i want to switch back to windows, however i get an error message "Error loading operating system" after the initial boot while installing windows xp.

Can someone please help me? I searched google and got a rough idea that it is related to boot loader. I would really appreciate if ubuntu community could help me with this matter.

BTW, i also formatted C drive (primary drive on which i wish to install windows xp) using Partition editor in live cd of ubuntu 9.04.