Retrieve computer uptime

gistfile1.cs

public static TimeSpan GetUptime()
{
     ManagementObject mo = new ManagementObject(@"\\.\root\cimv2:Win32_OperatingSystem=@");
     DateTime lastBootUp = ManagementDateTimeConverter.ToDateTime(mo["LastBootUpTime"].ToString());
     return DateTime.Now.ToUniversalTime() - lastBootUp.ToUniversalTime();
}