Virtual machine “Edit Settings” are greyed out or not available for a virtual machine in the Virtual Infrastructure Client (VIC)
1) Putty to a host in the cluster (I always Putty to the host the target vm is on) and edit the vm's "edit vmx file" or the vmx` file with the tilde on it. Do not edit the vmx file directly.
2) Change the value from "true" to "false" on the device place holder for the "CD-ROM" device using VI Editor.
ide0:1.present = "TRUE"
2a) Enter *i "insert mode", make the edit
2b) Type the esc key to exit VI edit mode
2c) Type :wq to save the file and exit VI Editor
3) Restart the management agents on the ESXi host using Putty or iLO to the ESXi host's DCUI.
4) Check to see if the vm's "Edit Settings" are available (probably wont be yet) in VIC.
5) Disconnect the host.
6) Reconnect the host.
7) "Edit Settings" are available now. Change the CD-ROM to Client Device, pass through IDE mode.
8) Migrate vm or enter Maintenance Mode.