Collect network computer details

i have written a program to collect details from remote computers in the network

private RemoteSysInformation.SystemInformation sysinfo;

if (sysinfo.Get(ipaddress, username, password) != RemoteSysInformation.SystemInformation.Status.Success)
{
    MessageBox.Show(sysinfo.Get(ipaddress, username, password).ToString());
}        
else
{
    List.Items.Add(new ListViewItem(new string[] { "BIOS Version", sysinfo.Bios }));
    List.Items.Add(new ListViewItem(new string[] { "OS Name", sysinfo.OSName }));
    List.Items.Add(new ListViewItem(new string[] { "Version", sysinfo.OSVersion.description }));
    List.Items.Add(new ListViewItem(new string[] { "OS Manufacturer", sysinfo.OSManufacturer }));
    List.Items.Add(new ListViewItem(new string[] { "System Name", sysinfo.ComputerName }));
    List.Items.Add(new ListViewItem(new string[] { "Time Zone", sysinfo.Timezone.standardname }));
    List.Items.Add(new ListViewIte开发者_如何学运维m(new string[] { "Windows Directory", sysinfo.WindowsDirectory }));
    List.Items.Add(new ListViewItem(new string[] { "Total Physical Memory", SizePrettyPrint(sysinfo.TotalPhysicalMemory) }));
    List.Items.Add(new ListViewItem(new string[] { "Available Physical Memory", SizePrettyPrint(sysinfo.FreePhysicalMemory) }));
    List.Items.Add(new ListViewItem(new string[] { "Total Virtual Memory", SizePrettyPrint(sysinfo.TotalVirtualMemory) }));
    List.Items.Add(new ListViewItem(new string[] { "Available Virtual Memory", SizePrettyPrint(sysinfo.FreeVirtualMemory) }));
    List.Items.Add(new ListViewItem(new string[] { "Page File Space", SizePrettyPrint(sysinfo.PageFileSize) }));
    List.Items.Add(new ListViewItem(new string[] { "System Manufacturer", sysinfo.SystemManufacturer }));
    List.Items.Add(new ListViewItem(new string[] { "System Model", sysinfo.SystemModel }));
    List.Items.Add(new ListViewItem(new string[] { "System Type", sysinfo.SystemType }));
    List.Items.Add(new ListViewItem(new string[] { "Domain", sysinfo.Domain }));
}

but its keep giving the error RPC service unavailable PLEASE HELP!!!!!!!!!!!!!!!

The error is The RPC server is unavailable. (Exception from HRESULT: 0x800706BA).

Make sure service Winmgmt (Windows Management Instrumentation) is running on remote computer.

Is the error message "RPC server unavailable" or "RPC service unavailable"?

• Is the remote machine up?
• Is the remote machine on the same LAN?
• Does the remote machine allow remote connections?
• Does the user you're specifying have the right permissions on the remote machine?
• Is there a firewall on the local and/or remote machines?
• Is there a firewall between the local and remote machines (maybe dropped RPC packets)?
• Are your DNS settings correct?
• What are the option. settings? For example, options.EnablePrivileges?