1.9 to 2.0 Upgrade is erasing all my data

I'm having issues upgrading from 1.9 to 2.0.
I've tried it multiple times and each time it is erasing all the products, categories, orders, etc data.
Only thing it retains is customer data.
Each time I've made sure that sample data is unchecked during installation, but i'm still losing all my data.
Anyone have had the same problem?

where are the experts ?

have you also run the update script that must be run after the setup wizard?

This moves all your data from the old tables "Nop_TableName" to the new tables "TableName"

i.e. this is Step 4 of the update process found in Readme.txt

"4. Execute upgrade.sql script over your database"

Yes I ran the script but still having the same issue.

Its a bit confusing...
make sure your DB is backed up.
You need to delete all the files in your website directory (after backing them up of course, I zip them)
Plop the 2.0 aspx files in the directory.
Go your your store site run the www.mystore.com/install installer, but be sure to not creade sample data and reconnecto to your old db.

** After the installer is done run the upgrade.sql script. **

-Mike

I work fine with the upgrade, step as below:
backup the website folder, and database first.
install 2.0, then run it like a new installation.
use same database name and login name ... etc during the installation.
and run the website. and you will see nothing inside the store, (because 2.0 create new table for you, and your old Data still keep in the database but old table name)

then run the upgrade script, the script will move all data into your new table.
and done.

but make sure before you run the script, logon the store admin page and setup country, measure ... most important the media location too.
the default media location is in database, it won't show the picture if your pictures store into the image folder.

hope can help.
sorry for my bad English