VMware Workstation : This virtual machine appears to be in use.If this virtual machine is already in use, press the “Cancel” button to avoid damaging it.

When working with VMWare Workstation 8, you should always make sure to suspend or shutdown your running virtual machines in VMWare Workstation. 
If you reboot your host / client, while VM’s are running, VMWare Workstation 8 then may keep your virtual machines files locked., so no other program or process can access or alter the files.

The following error then occurs when you try to access the VM after the reboot:

VMware Workstation 8: This virtual machine appears to be in use. If this virtual machine is already in use, press the “Cancel” button to avoid damaging it. If this virtual machine is not in use, press the “Take Ownership” button to obtain ownership of it. Configuration file: “your location to the VM".vmx”

Cancel will do noting. Clicking “Take Ownership” will result in the next error:

Taking ownership of this virtual machine failed. The virtual machine is in use by another application on our host computer. Configuration file: “your location to the VM".vmx”

To resolve this issue, simply delete the *.lck directories in your VM-directory. In the case of aboves screenshots, you will find the *.lck directories in C:\Virtual Machines\SRVStarwind

After deleting the lock-directories, your VM should be able to start just fine…