I am using virtual machines for development,but each time I need a new VM, I copy the file and create a new server, but I need a new name for the server to add it to our network.
After renaming the server, the Sharepoint sites have many errors and do not run.
Here is a Technet article that might be helpful: http://technet.microsoft.com/en-us/library/cc261986.aspx
If you are going to uninstall SharePoint check this article for more details about SQL Server rename: http://technet.microsoft.com/en-us/library/ms143799.aspx