Hello and welcome to the forum
When an XP install sees other attrached drives, including zip and flash drives, it assigns C; to the first one and moves down the list to a unused letter ( in your case I ). This is a little hickup and the only way around it is to reinstall with all other drives disconnected.
This time around, look closely at the screen that is after the "
Press F8 to accept" prompt, where you can delete partitions to see what it shows . . delete all of the partitions, then create new one(s) the size you want going forward.
After the installation, you can reconnect the flash and other drives.
When you get to the partitioning screen, post back and tell us what you see