Update from cubase 5 to 7

I would like to update from cubase 5 to version 7.
I dont know where to find my registration number and im running windows xp on my pc.

When i bought cubase in 2008 it was version 4. at the time i had and engineer working with me and he did all the neccesary registrations.
Am i still eligable for updates and will steinberg still have a record of my license number.?

Can anyone help ?

To update, you don´t need old registration numbers, you need a valid Cubase 5 license on your USB eLicenser

If he has done it correctly, he should have created a “mySteinberg” account for you, which holds all those infos. And which you should have the access data to.