After installation of V7 caused problems, V6 was installed but could not be completed due to corrupt data. I must uninstall both versions. How do I do that ?
You need to delete the database because the version 7 one is not backwards compatible with version 6. To do that, close eM Client 6, and then delete or rename C:\Users_username_\AppData\Roaming\eM Client. You may have to show hidden items in Explorer to do that.
When you start version 6, you will be prompted to setup an account etc.
There are many benefits to using version 7 over version 6. If you would like to address any problems you had with version 7, I am sure somebody here will be able to help you.
When I try to start eM Client, the program checks for inconsistent data and signals SQL logic error or missing database. "No such table:mail_index. Mailitems
Delete or rename the database and try again.
I understand I need to d 
elete or rename the database, but which one is it ?
It is the whole \eM Client\ directory.
what about the registry settings ? Shouldn’t I uninstall all EM Client directories, clean up the registry and start a new installation ?
That is not really necessary, but if you want to do that you can.
Up and running ! Thank you
Why is v7 3+ times larger than v6? That’s a HUGE difference.
Could be a number of reasons. The databases are a slightly different format so there would be some difference. If conversations are enabled that increases the size of the database. If you now have IMAP enabled for offline use, that would also do it. If you upgraded from a version 6 database to a version 7, the old database will still be there in the same folder if you did not choose to remove it after the conversion.
I was referring to the original installation file from the website. 15MB vs 51MB.
Oh OK. Yes, you are correct. Maybe that means it is 3 times better. 