Jackie,
I guess that you replied 'yes' to a message you got, asking if gauge files you were adding should over-write existing ones.
You can replace the standard gps.gau from the original FS2002 CDs. Can't remember which one it's on, but there is a .cab file containing all the gauges that you can open with Winzip. Copy gps.gau from there back to your FS2002 gauges folder and Hey Presto.
