I am doing my preprocessing utilizing matlab 7.5 on a pc. Preprocessing appears to work fine but matlab repeatedly spits out various warnings during this. For example: Warning: In the directory "C:\Program Files\spm\spm5", mat2file.mexw32 now shadows mat2file.dll. Please see the MATLAB 7.1 Release Notes. > In file_array.subsasgn>subfun at 125 In file_array.subsasgn at 63 In spm_write_plane at 33 In spm_uw_apply at 344 In spm_config_realign_and_unwarp>realunwarp at 793 In spm_jobman>run_struct1 at 1585 In spm_jobman>run_struct1 at 1595 In spm_jobman>run_struct1 at 1595 In spm_jobman>run_struct at 1514 In spm_jobman>run_ui at 2249 .... I know that other people have posted similar messages on here. I've seen that this can be changed by moving some of the files. My question is: If I don't move the files and continue to get these warnings during preprocessing will it affect my data in any way? I'm wondering if data I have preprocessed needs to be repreprocessed after getting rid of these warnings. I have no problem with continuing to get these warnings as long as it is not affecting my data. Thanks, Brian