XAMPP, Apache - Error: Apache shutdown unexpectedly

I've just re-installed XAMPP, and when I try to start my Apache server in the XAMPP Control Panel, I now get the following errors:

16:50:25  [Apache]     Status change detected: running
16:50:26  [Apache]     Status change detected: stopped
16:50:26  [Apache]     Error: Apache shutdown unexpectedly.
16:50:26  [Apache]     This may be due to a blocked port, missing dependencies,
16:50:26  [Apache]     improper privileges, a crash, or a shutdown by another method.
16:50:26  [Apache]     Press the Logs button to view error logs and check
16:50:26  [Apache]     the Windows Event Viewer for more clues
16:50:26  [Apache]     If you need more help, copy and post this
16:50:26  [Apache]     entire log window on the forums

Answers : 

As I am working in a corporate environment where developers faces firewall issues, none of the other answers resolved my issue.
As the port is not used by Skype, but by some other internal applications, I followed the below steps to resolve the issue:

Step 1 - From the XAMPP Control Panel, under Apache, click the Config button, and select the Apache (httpd.conf).
Inside the httpd.conf file, somehow I found a line that says:
Listen 80
And change the 80 into any number / port you want. In my scenario I’m using port 8080.
Listen 8080
Still from the httpd.conf file, I found another line that says:
ServerName localhost:80
Change 80 to 8080.
ServerName localhost:8080

Step 2 - From the XAMPP Control Panel, under Apache, click the Config button again, but this time select the Apache (httpd-ssl.conf). Inside the httpd-ssl.conf file, find line that says
Listen 443
And change the 443 into any number / port you want. I’ll using 4433 as the new port number.
Listen 4433
Still from the httpd-ssl.conf file, find another line that says

<VirtualHost _default_:443>
ServerName localhost:443
And change 443 to 4433.

<VirtualHost _default_:4433>
ServerName localhost:4433


Remember to save the httpd.conf and httpd-ssl.conf files after performing some changes. Then restart the Apache service.

if still issue is pursuing then do it below given steps also: 

IMPORTANT Deleting this file may render any existing MySQL data unusable. Use with caution

Hey I just did this and it worked:

exit Xampp server

go to your C:\xampp\mysql\data directory

delete the ibdata1 file

restart xampp server

It should work