VMware Workstation says "VMware Tools Unavailable"

If you are not able to install VMware Tools, it is probably because you specified the "Guest operating system" as "other".  You may have chosen "other" for reasons like testing a live CD.  VMware will select the right VMware Tools when you specify the operating system such as Microsoft Windows and Linux as VMware Tools ISO files differ among operating systems chosen.  Selecting other leaves you doing it manually.

You might have tested your live CD and later on decided to install it to the hard disk and then after that you needed to install VMware Tools.  Right clicking on the virtual machine will show "VMware Tools Unavailable" and grayed out.

If you happen to know the operating system, then you have to add the right VMware Tools manually as an ISO to the CD/DVD (IDE) by navigating to the iso file to where you've installed your VMware Workstation.  That's where the VMware Tools reside.  After you do that, you can then access the virtual CD from the guest operating system and install the VMware Tools.