Hello John - I just googled your email address sarchs.com and I found St Augustine's RC School in Lancs. It may be (sorry if I have totally got it wrong) that you are ex-CLEO Lancs Moodle and have moved to your own hosting, on Windows. If that is the case then I suggest you get in touch with Geoff Diggles the network manager at Our Lady's Preston (site in link) as he set up Moodle for the school (my old school) on Windows in exactly the same cirumstances and had speed issues too, which are mostly resolved - so he might have some advice for you. (You can tell him I told you )Unfortunately, although Moodle does work on Windows, not as many people have it running and contribute here on the forums. If you do a search on these forums you will probably find Geoff's posts from last year, and you will also find some very helpful Moodlers running Windows here who will make some good suggestions. But in terms of similar experiences, feel free to get in touch with Geoff.
It would be useful to future posters too, if you can post back with some of the things you find which succeed in increasing the speed of your Moodle