Hi, I have a ruby utility running on a windows box with 1.5Gb of memory However, when it's memory usage gets to about 250Mb (i.e. total system memory usage 320.5Mb) it crashes with the following message:- pp_main.rb in clone : add_heap : can't alloc memory <fatal> I suspect that either windows doesn't think it has all the memory that is in the system, or windows won't let it have it. Any ideas? Thanks Steve Dr Stephen Hill Systems Engineering Analysis Motorola GSD