tomron,

You cannot change the drive letter on an active "system" drive, go ahead and try, it won't let you.

This link explains how to change drive letter.

 

http://support.microsoft.com/kb/307844

I would think that you did not delete the partitions and create a new one(s).  That would be the only way that Windows would have created a new partition named I.

 

What does the Disk management Applet show for partitions?

Sounds like something was not done properly during the re-installation process.

 

Once XP is installed the assigned drive letter cannot be changed.

 

 

You would have to reinstall the OS to do this.