Start process Explorer ( V16.02 ) C:\tools> procexp Use process explorer and find Find Handle or DLL supstring : grac41.vdi VirtualBox.exe VirtualBox.exe 136.112 K 100.040 K 1972 Oracle VM VirtualBox Manager Oracle Corporation VirtualBox.exe 5068 File E:\VM_HOME\GRAC11204\grac41.vdi File E:\VM_HOME\GRAC11204\grac41.vdi Note with process explorer you close this file -->In the file Handle window press right mouse button and select : CLOSE HANDLE