Don't use "root" for installs on XAMPP, or anywhere
This may or may not help, but something that happen to me and I see some others with similar issues.
I had to do a wipe and upgrade of my PC due to jumping versions of Linux... normal event, so did my backups of all my testing and active ZC installs. As I was rebuilding my OS, I also downloaded a new xampp install and set it up. 'xampp-linux-x64-1.8.3-4-installer.run'
came with:
Apache 2.4.9 (Unix)
OpenSSL 1.9.1g
PHP 5.5.11 (Zend: 2.5.0)
MySQL 5.6.16
Server OS: Linux 3.13.0-36-generic
Everything went as expected and seamed to be working, until I accessed one of my test sites...
Problem:
Front of the store was a mess, no template, products so on.. tried to access admin, could not log in, didn't recognize the user or password. Came back to the forum and found hacks to fix admin login, did that, no luck. Tried a new install using ZC 1.5.3, it crashed and would not finish installing... again, tried some of the fixes and even thought that the installer sql syntax was off... I finely, got a message that said no 'connection to database' that's what I need to fix.
Solution:
There is no problems with ZC, may need to change some of the install instructions someday, but it's still the best cart program I've came across. The problem is with MySQL 5.6.16 and I'm not sure how far back this goes... ROOT user is not allowed access outside of phpmyadmin or root shell account. So if you created the database and left root as the only user, give root to the config files, you are not getting into that database until you resolve the user access issues, which means you can't use ROOT as the store database user anymore. It's about time this process became easer to do and it keeps host from restricting you from creating users...
So, before you install/upgrade you need to access phpmyadmin for your account.
1) create a new database user with a strong password.
2) Create the database that you will use for your site.
3) From the new database, add the user and assign privileges... do not use 'GRANT'.
If you don't use 'create, alter, or drop' you wont be able to install/remove mods from the ZC admin.
this should be normal..

Now you can continual with the install/upgrade as you would of before... be sure to add this user in your config files and not root. The user and database in the image no longer exist..
so, lesson learned... always create a database user!! Passing it along
Dave
Always forward thinking... Lost my mind!