WMP Library

Good afternoon everyone, I'm running XP Home SP3.
Recently I have the power supply go out in the computer and after the new one was installed and all peripherals connected, Windows installed the external hard drives in a different order. So now all my music in on the J drive instead of the I drive and WMP can't find the tracks.
So in WMP I went to options/library and deleted the I drive reference and added a J drive folder to monitor, for future reference only. If WMP is open it will in the background start to add the tracks from the new locations, but will that cause double tracks in the library?
So is WMP smart enough to recognize the songs or albums meta data and just correct the link or would it be better to delete the old library and recreate it (overnight!). If so, how do I delete the library without effecting anything else?