Bob, let me start by thanking you for all your advise.

This kind of things makes me jumpy, just because it is Terra incognita.

I have spent the best part of the evening reading al kinds of articles, inclusing your suggestions.

Apart from that: before I started installing enterprise I have made a restore point, as well as a image from the C-drive.

I have used the restore point. After this still a lot of SQL server options were available under "all programs".

I then used "programs and features" to uninstall SQL Server 64 bit. This proces gave no problems and there are no (SQL Server) options left in "all programs".

However: there is still an option to start "Microsoft Visual Studio 2010", and that still works. It opens but has only a few options, not the same as there were before.

Also: in "programs and features" there are still a lot of SQL Server programs visible, most are dated on the day Express was installed.

And, not surprisingly, there are references here to Visual studio

If I look in Services, there is no reference to SQL Server at all.

My question: what to do with the remaining SQL Server and Visual studio programs in "programs and features"?

Leave them and install Enterprise again, or should this cause problems?

Hein