Solved : Cannot retrieve repository metadata (repomd.xml) for repository

I just install CentOS 6.4 and use yum install update but got

“Cannot retrieve repository metadata (repomd.xml) for repository: Please verify its path and try again”

I have double check with nslookup , ping and general internet browsing and everything seems me fine but update didn't work. I also tried yum clean all etc. but what work for me is here;

Solution :  

1. Open a terminal (become Super user by entering 'su' and then the password)
2. Type cd /var/run/
3. Than Type dir to look for the 'yum.pid' file.
4. Type rm -f yum.pid and press Enter
5. Again Type dir to Confirm that the 'yum.pid' file has been deleted.
6. Now again try yum update

Hope this will resolve your issue, I have done this on CentOS 6.4 but I have a great hope that it will also work for fedora, RedHat as well. please show yourself in comments;