Hi Francisco,
Before attempting an upgrade, it’s best practice to always back up your files and your database. It’s so important, in fact, that it’s the first thing we tell you to do when preparing for an upgrade. There may be instances where you need to roll back your installation, and this is one of them. Here’s why:
EE 2 introduces some new database tables and columns that don’t exist in EE 1. There are also some database tables from EE 1 that will be removed as you upgrade into EE 2, but if your installer hadn’t gotten that far, then your database would consist of all your EE 1 tables plus some new EE 2 tables. In this case, your installation at 1.6.8 would still work fine, but if you try to upgrade that installation, the EE 2 upgrade script will try to add new tables, columns, etc. to the database that already exist, and you’ll encounter some big MySQL errors.
So until you can restore your database to exactly the way it was in 1.6.8, you’re going to encounter problems trying to upgrade. Does this make sense?
Sometimes web hosts do routine backups of their clients’ databases. Perhaps you could work with your host to see if you can get a recent backup restored.