Having problems with Mail and a few other programs freezing
First off, congratulations on upgrading to a Mac, I'm a Windows "switcher", too, and will never go back. Secondly, as far as reinstalling a fresh copy of OS X (pronounced oh-es-ten NOT oh-es-ex) you will want to turn your MacBook off, then turn it back on, but while holding the Option key. Release it when you see two icons of hard drives, whatever you named your startup disk ("Macintosh HD" by default) and one labeled Recovery. Select Recovery by highlighting it with the arrow keys, and then hitting the enter key. Once there, you should see the option to "Reinstall OS X" select it and just follow the on-screen instructions from there. Make sure to select your start up disk, again named "Macintosh HD" by default, where it asks which drive to reinstall it on.