How to delete old OP systems

Got my Mom a used computer from a friend was have problems with it on bootup was asking which xp home to start?? think they loaded it two times
anyway I have xp pro that I put on it and when I loaded it was asked to undo the partitions on the hard drive and wipe it clean well I loaded xp pro in it and it runs fine but when I bootup it asks which op to I want to run is showing two xp homes and xp pro to start..how and what did I do wrong and how to I get the xp home versions off if it..