Abstract: A method for recording data on a magnetic recording medium is disclosed. When data are written to a target track Tn, the numbers of effects on tracks Tn?1 and Tn+1 adjacent to a target track are counted as Adjacent Track Interference (ATI) effect counts Cn?1 and Cn+1, respectively, to determine whether or not the ATI effect counts Cn?1 and Cn+1 are greater than a permissible ATI count Np. If the ATI effect counts Cn?1 and Cn+1 are greater than the permissible ATI count Np, ATI error preventive processing is performed on the tracks Tn?1 and Tn+1. All sectors on the Tn?1 and Tn+1 are determined as to whether or not they are affected by ATI, and ATI error counter-measure processing is performed on all affected sectors to recover data.