Toshiba said Monday that it will offer a free exchange program for more than 25 of its notebook models, caused by <A HREF="http://www.eweek.com/article2/0,1759,1706577,00.asp">a problem with a memory module</A> that appears similar to one that affected Hewlett-Packard several months ago. Toshiba said it had placed a downloadable utility on its Web site so users can determine whether they are affected by the problem. If they are, users can send in the module free of charge and receive a replacement.