System.InvalidCastException: 'Specified cast is not valid.'

Question

run time exception on line this

 

ManagementObjectSearcher searcher1 = new ManagementObjectSearcher("SELECT * FROM Win32_LogicalDiskToPartition");

foreach (ManagementObject dm in searcher1.Get())   //exception at this point

{

diskArray = null;

driveLetter = getValueInQuotes(dm["Dependent"].ToString());

diskArray = getValueInQuotes(dm["Antecedent"].ToString()).Split(',');