students who are here for 6 months+ have full access to the NHS, there shouldn't be a question about that. The stuff that ksand posted is in regards for students who are here for under 6 months (ie on a semester study abroad or short course), which sounds right.
When I studied in the UK for under 6 months back in 2005, I was required to have private medical insurance in case I needed a lengthy hospital stay or something like that, but I could also access basic treatment at the university health practice for free (even though it's an NHS practice I'm assuming the university contributed to the costs of treating foreign students who were here for only a few months, who aren't entitled to use of the NHS.) When I came back to the UK to study for a 12-month masters degree, I registered at a regular GP practice with no issues and had full access to any NHS service I might have needed.