Forgot about making this plea for help (among others) after I found a solution - yes it turned out to be windows fault. I had to add a pair of lines to my http.conf file. For the sake of those watching who might be suffering similar problems those lines were
EnableSendfile off
EnableMMap off
Put them at the end of the file, and don't automatically assume you need this on a WinXP installation. On my laptop I apparently didn't need them.
:shrugs:
Thanks for the reply though