Well ****** me! I deselected the option to let windows manage its own virtual memory and reselected 384mb for the lower figure and 1536mb as the upper figure (as it is exactly twice the lower figure and double the previous higher figure) and everything seems to be working fine! The virtual memory problem had been stopping my printer from functioning but even that is working now (as best as it can with these poxy XP drivers!).
Thanks very much everybody, especially carbheatcold for the solution and Flex for the interesting web site.
I hope this page gets revisited if anyone else has the same problem and remembers to us the prune search facility.
Regards
wizzy