problems installing on xampp

Hi I all of a sudden have problems installing a new modx install in xampp/htdocs/folder.
I downloaded evo again, running about 5 modx installs local, evo and revo all running okay.
Error is in new install:

Creating database tables: Database Alerts!

MODx setup couldn’t install/alter some tables inside the selected database.

The following errors had occurred during installation

Advanced upgrade:

Checking table prefix ``: FAILED! - Table prefix does not exist in this database!

Setup couldn’t install into the selected database, as it does not contain existing tables with the prefix you specified to be upgraded. Please choose an existing table prefix, and run Setup again.

Any ideas?

XAMPP 1.7.3
Apache/2.2.14
MySQL client version: 5.1.41
Windows 7
correction all websites gone dead is there a way to reset xampp?

Try creating the DB manually in PhpMyAdmin before running the install.

Reset by stopping and re-starting Apache in the XAMPP control panel (or rebooting).

did that, rebooted machine, re downloaded MOdx. Dropped db, no go.
I am following this php course and we started doing stuff to Mysql over the CL.
I at one point got stuck and could not exit. Will just coimpletley re-install xampp.

Done, all okay again.