I've just had this trouble - and frustrating it was too!
I'm also in the UK and eventually I found this HP site by pretending to be American:
h t t p colon slash slash** h20000.www2.hp.com/bizsupport/TechSupport/SoftwareIndex.jsp?lang=en&cc=us&prodNameId=374576&prodTypeId=18972&prodSeriesId=360489&swLang=8&taskId=135&swEnvOID=228
**The URL expressed in the usual way was disallowed because this is my first post on this forum, but this URL is the whole point of the post. I'm just trying to be helpful!!
It's probably too late for you, Jonti007, but others may benefit.
I cleared as much of the debris from the Polish/Czech* installation as I could by using the HP software removal utility (on that page), desktop icons, related folders, temporary files, and irrelevant registry entries (using Macecraft jv16 PowerTools). This may not have been necessary, but I wasn't going to be wasting any more time on abortive installations.
*Apologies to Poles and Czechs but I've seen forums that refer to both languages and I really don't know which language it is - it's all Greek to me!
I installed the basic driver successfully and decided to go for the full feature driver. So I cleared the decks again and downloaded the 300-odd MB driver.
This installed successfully. It's probably also worth downloading the other relevant files such as diagnostics, help utility etc. You can download these from the same site.
Good luck to anyone who's had the same unfortunate experience as Jonti and me!