C# Get hardware information whith WMI

WMI.cs

/// <summary>
/// Use WMI for check percentage of CPU Usage
/// Write to private field _cpuUsage
/// </summary>
private void CheckCpuUsage()
{
    try
    {
        var searcher =
            new ManagementObjectSearcher("select * from Win32_PerfFormattedData_PerfOS_Processor");
        var cpuTimes = searcher.Get()
            .Cast<ManagementObject>()
            .Select(mo => new
            {
                Name = mo["Name"],
                Usage = mo["PercentProcessorTime"]
            }
            ).ToArray();
        _cpuUsage = (ulong) cpuTimes[0].Usage; //atomic assignment
    }
    catch (Exception exception)
    {
        CheckCpuUsageErrors++;
        _subscriberOnMessages($"Error on checking cpu usage: {exception.Message}");
        _subscriberOnMessages($"Total errors on checking cpu usage: {CheckCpuUsageErrors}");
    }
}

/// <summary>
/// Use WMI for check RAM usage (int %)
/// Write to private field _memoryUsage
/// </summary>
private void CheckMemoryUsage()
{
    try
    {
        ManagementObjectSearcher searcher = new ManagementObjectSearcher("SELECT * FROM Win32_OperatingSystem");
        var hddUsage = searcher.Get().Cast<ManagementObject>().Select(m=>new
        {
            TotalVisibleMemorySize = m["TotalVisibleMemorySize"],
            FreeMemory = m["FreePhysicalMemory"]
        }).FirstOrDefault();
        if(hddUsage == null) throw new Exception("Can't recive informacion about memory usage.");
        var freeRam = (ulong) hddUsage.FreeMemory;
        var totalRam = (ulong) hddUsage.TotalVisibleMemorySize;
        _memoryUsage = (totalRam - freeRam)/(float)totalRam * 100;
    }
    catch (Exception exception)
    {
        CheckMemoryUsageErrors++;
        _subscriberOnMessages($"Error on checking RAM usage: {exception.Message}");
        _subscriberOnMessages($"Total errors on checking RAM usage: {CheckMemoryUsageErrors}");
    }
}

/// <summary>
/// Use WMI for check HddUsage (PercentDiskTime)
/// Write to private field _hddUsage
/// </summary>
/// <param name="diskLetter">Disk name in format: "D:\\"</param>
private void CheckHddUsage(string diskLetter)
{
    diskLetter = diskLetter.Replace("\\", "");
    try
    {
        var searcher =
            new ManagementObjectSearcher("select * from Win32_PerfFormattedData_PerfDisk_PhysicalDisk");
        var hddUsage = searcher.Get()
            .Cast<ManagementObject>()
            .Select(mo => new
            {
                Usage = mo["PercentDiskTime"],
                Name = mo["Name"]
            }).ToArray();
        for (var i = 0; i < hddUsage.Length; i++)
        {
            if (!hddUsage[i].Name.ToString().Contains(diskLetter)) continue;
            _hddUsage = (ulong) hddUsage[i].Usage; //atomic assignment
            break;
        }
    }
    catch (Exception exception)
    {
        CheckHddUsageErrors++;
        _subscriberOnMessages($"Error on checking hdd usage: {exception.Message}");
        _subscriberOnMessages($"Total errors on checking hdd usage: {CheckHddUsageErrors}");
    }
}

/// <summary>
/// Use WMI for check amount of free memory
/// </summary>
/// <returns>Amount of free memory in bytes</returns>
private ulong GetFreeMomory()
{
    try
    {
        ManagementObjectSearcher searcher = new ManagementObjectSearcher("SELECT * FROM Win32_OperatingSystem");
        return searcher.Get().Cast<ManagementObject>().Select(m => (ulong)m["FreePhysicalMemory"]).FirstOrDefault() * 1024;
    }
    catch (Exception exception)
    {
        _subscriberOnMessages($"Error on checking free RAM: {exception.Message}");
        _subscriberOnMessages(exception.StackTrace);
        return 0;
    }
}

/// <summary>
/// Use WMI for check type of disk
/// </summary>
/// <returns>One of DiskTypeEnum: Hdd or Ssd</returns>
private DiskTypeEnum GetDriveType(string diskName)
{
    try
    {
        char driveLetter = diskName[0];
        if(driveLetter < 'A' || driveLetter > 'Z') throw new Exception("Failed to recognize drive character.");

        using (var partitionSearcher = new ManagementObjectSearcher(
        @"\\localhost\ROOT\Microsoft\Windows\Storage", "SELECT * FROM MSFT_Partition"))
        {

            var partitions = partitionSearcher.Get().Cast<ManagementBaseObject>();
            ManagementBaseObject partition = partitions.FirstOrDefault(managementBaseObject => (char) managementBaseObject["DriveLetter"] == driveLetter);
            if(partition == null) throw new Exception("Filed to recognize disk partition containing file.");

            using (var physicalDiskSearcher = new ManagementObjectSearcher(
                        @"\\localhost\ROOT\Microsoft\Windows\Storage", "SELECT * FROM MSFT_PhysicalDisk"))
            {
                var physicalDisk = physicalDiskSearcher.Get().Cast<ManagementBaseObject>().FirstOrDefault(m=> ((string)m["DeviceID"]).Contains(((uint)partition["DiskNumber"]).ToString()));
                if (physicalDisk == null) throw new Exception("Error on WMI request of disk type");
                if (((ushort) physicalDisk["MediaType"] == 4) && ((uint) physicalDisk["SpindleSpeed"] == 0))
                {
                    return DiskTypeEnum.Ssd;
                }
                return DiskTypeEnum.Hdd;

            }
        }
    }
    catch (Exception exception)
    {
        _subscriberOnMessages($"Error on getting disk type: {exception.Message}");
        _subscriberOnMessages(exception.StackTrace);
        return DiskTypeEnum.Hdd;
    }
}

The title is wrong written:
"C# Get hardware information whith WMI" needs to be corrected to "C# Get hardware information with WMI".
("with", not "whith"!)