Hi Theog, yeah, the first time I tried it I left it overnight. It turns out is was the hardware driver issue, I had to disable pretty much everything to get it to install, then switch them all back on again once the desktop was running, Almost all anyhow, a couple wouldn't activate and still need sorting out.
Right so I thought I'd try the online activation before phoning ------and it worked, go figure

I now have a correctly activated copy of Windows 7, complete with shiny "genuine microsoft" sticker.
Now I just need to get the mysterious "unknown hardware" working and get the USB ports going again.
---Thanks Acer
Oh and proper real non-sarcastic thanks to you Gregrocker and Theog for your help