ok, you remember the good old days when 500 Mb hard disk drives where considered huge, how easily you installed lots of crap on it, and then how hard it is to remove it just to install some more crap. now its a bit the same with coLinux, the default images that are supplied are rather small for a good reason (they must fit on the disk once uncompressed :) and usually range from 1 Gb to 2 Gb. now you can enlarge them to a bigger size, move all your files to a bigger filesystem image, but sonner or later you will have to do some housekeeping.