All projects gone after TeamCity 8 upgrade

Hi

I upgraded TeamCity to version 8 and while it's installed fine, it now looks like a fresh installation rather than upgrading my existing installation.

Here's what I had earlier:

TeamCity v6.5 in C:\TeamCity
Data directory: D:\TeamCity\Data

I then installed v8 into c:\TeamCity, and it correctly uninstalled the previous version.
I told it to use D:\TeamCity\Data for the data directory

I have backed up the Data directory previously, and I also have a snapshot of the entire server so I can recover everything. But I would really like to get v8 up and running tonight.

Does anyone know why it went wrong? Can I re-run the installer and somehow make it recognise all the old projects/settings etc?

Thanks