Well - if you are just getting started, I would un-install the current XAMPP, and install XAMPP 1.7.3 - its much more stable (unless you have some version-related reason to run 1.7.4).
Well, I guess I need a how-to-uninstall-XAMPP page!
Basics -
A. Save or backup any files or folders you have created. If you are using MySQL, and wish to preserve any databases, you will need to do a MySQL backup, a file-based backup will not work.
B. Be sure to remove the 'Services' you may have running before uninstalling XAMPP - uncheck the Svc box before those services currently running - Apache, MySQL, FileZilla and/or Mercury. Reboot the machine, check the XAMPP Control Panel and ensure the Svc boxes are not 'unchecked'. Close the XAMPP Control Panel.
C. You should now be clear to remove the XAMPP folder and its sub-folders.
Good Luck