Follow the steps to solve your problem:
1_ open xammp
2_ click config in apache line
3_ click Apache(httpd.conf)
4_ search for '80'(Default Port) and change it to any number. ex: 81,82....
  change:
  1_ #Listen 12.34.56.78:80 to 81
  Listen 80 to 81
  2_ ServerName localhost:80 to 81
5_ save and exit.