Hello Richard.
You may have a corrupted phpMyAdmin installation as I have just tested using phpMyAdmin 3.4.5 in XAMPP 1.7.7 and I could create a database
newdb and a user with password for that database in much the same way as the previous versions (only slight variations as now there are new frames created and I prefer to right click on the links to create the frame in a new tab).
After I created the newdb database I clicked on
Privileges tab and selected
Add New User.
I added
newdb user name for
localhost and gave it a
password.
None for database selected.
Then I click
Create.
In the list of Users in the Privileges table I clicked on the
newdb user so it had a tick in the box then on
Edit privileges.
Then under
Database specific privileges I clicked on the
Add privileges on the following database drop box and selected the
newdb database.
Then when the Window changes to add specific privileges I selected
Check all and then on
Go.
I then received a confirmation window that all was created as I had entered the information.
Next I click on the main
Privileges tab to check my new user
newdb has:
User: newdb
Host: localhost
Password: Yes
Global privileges: USAGE
Grant: No
All is well and as expected.
I notice that you have created 2 users and granted them Global privileges which is a big mistake.
You should create a password for super user root using the Security menu item in the XAMPP Admin page.
http://localhost/xampp/index.phpUser root should be the only user with Global privileges.
Following the above method you can edit the privileges of any user you create and give privileges to any specific database, in fact change anything related to a user.
Any user you create should only be granted privileges to a specific database only not to Global privileges as this could pose a security threat if ever that username/password combo was compromised.
If your XAMPP installation is suspect then you can follow these instructions to uninstall/install using a different method.
viewtopic.php?p=179699#p179699Good luck.