Yes you should be able to reinstall xp with the files in the I386 folder if you have the key for that
If xp was on the same drive as your I386 folder I would sugest partitioning your disk and install xp in a separate drive that way if something goes wrong you still have your files in the I386 folder
Since you don't have xp you will need something to boot your pc thabn you could use thei386 to reinstall