Hi,
Login thru vSphere Client in the Vcenter Server and
Right Click on that Particular VM -> Go to Edit Settings ->Click on Harddisk and check on DiskFile Tab (where is the VMDK file located on which Datastore)
After that Go to Inventory -> Datastores , find the datastore for that particular VM and Right click and click on Browse Datastore.
you will find some folder having ur VM folder also, Click on the Folder where is ur VMDK file is located at the upper tab
Find the below snap
After Click on Move it will ask for the confirm Move
After click on YES the move Items tab will show up
Click the Datastore and select the Destination Folder where u want or Make a New Folder for that Particular VM with naming and Click on Move.