Nokia Lumia 925. Can't Connect to Sign in to Microsoft Account.

Hey guys, I bought myself a cheap Nokia Lumia 925 in the hopes of just using it for internet browsing and Spotify.

It's locked to EE and I'm on Vodafone (UK), but I wasn't planning on inserting a SIM card at all, and just using it on WiFi.

Unfortunately, every time I try to sign in to my Microsoft account (via the initial setup, after trying to download an app, and through settings > email+accounts), I'm shown a message that contains the following:

>Can't connect

>We're having trouble signing in. Make sure you have good reception. If you do, you could try again in a little while.

I've checked online and tried soft, and hard resetting the phone to no avail. I've also tried the date/time trick that has solved it for a lot of other people. I've also tried going into Settings > Data Sense > and turning off "Restrict background data usage when roaming", which didn't work.

I'm at the end of my tether now. The only other thing I could think that it might be is that I don't have a SIM inserted, and it will only let me connect once I've done that (although, I really hope not because I'll have to contact EE to unlock the phone then), can someone please let me know if this is the case?

Thanks!