How can I solve my XAMPP installation problem?

As a part of my web development lesson I installed XAMPP on my PC as the localhost. For the first time, it works nicely. I keep a copy in another directory in my PC. After some days I format my PC, then try to install the XAMPP but the error message shows like this:

Error:

XAMPP 1.7.4 win32

Ports 80 or 443 (SSL) already in use! The installing Apache2.2 service failed!

However I install XAMPP but when I started to run for working as local host the message shows:

Error:

XAMPP Control

XAMPP Component Status Check failure [-858993460].

Current directory: c:xampp

Run this program only from your XAMPP root directory.

As a new user I am worried to proceed to next any step myself.

My question is, what is the problem with XAMPP installation and work with it?

Thanks in advance.