Switching from General Visitor to Tier 4

Hello,

I have been issued with a student tier 4 visa as I am going to university later this year. I wish to travel to the UK earlier than the visa allows me to therefore I need to know a) will immigration allow me to enter the country as a general visitor if they see I have a tier 4 visa, and b) to activate the tier 4 visa do I simple leave the UK and re-enter (Not necessarily returning to my home country).

Please note that I plan to have return flights, although the return is going to be in december so I can visit my family over christmas.

Thanks!

When does your tier 4 visa start? When do you want to visit and what is the purpose of this visit?

The tier 4 visa starts in August. I would like to come at the end of May to find a place to live and visit some friends.

Has your Tier 4 visa actually been issued yet? It is not normally possible to apply more than 3 months before the start of the course.