thanks for the reply, in fact I managed to solve it -but alas did not have the time to post here. Anyway , it looks like that that I messed up the re-install USB's, as at sometime ago I had the silly idea to make and keep an image of the recovery USB, but finally I managed to mix it with other recovery images then the one I used now was from a friend's venue, same model but the guy got it from USA.
So far I found that the USA model came with OEM bound to 8.1 Core, mine (UK) came with 8.1 Core with bing. way different versions. Problem is that the 8.1 with Bing from Dell is nowhere to found. After some search on the web I found the 8.1 with bing from MSDN (x19-57135-blahblah in my case), so I connected the venue with an OTG cable and powered hub and performed the installation. Windoze is activated like a charm. Bit messy recovery, but at least I have activated OS.