I'll bet you 100 to 1 I know this one! I've had the same problem and just found the answer an hour ago! In work I've got megamemory and at home just 64.My program crashed after the 1st pass through excel at home; at work 4 times. The problem is if you create excel as an object and close it only the object dies! The excel application is still alive and not so well in your computer's memory.When you set the objects to nothing do this: excel.application.quit and it should give you your memory back.Save any variables as public if you want to pick up where you left off when you reopen excel.Hope this helped.