I have ComputerA on DomainA running as userA needing to copy a very large file to ComputerB on WorkgroupB which has the ip of 192.168.10.2 to a windows share that only userB has write access to.

There is no netbios or dns resolving so the computer must be refrenced by IP

I first I tried

AppDomain.CurrentDomain.SetPrincipalPolicy(System.Security.Principal.PrincipalPolicy.WindowsPrincipal);
WindowsIdentity UserB = new WindowsIdentity("192.168.10.2\\UserB", "PasswordB"); //Execption
WindowsImpersonationContext contex = UserB.Impersonate()
File.Copy(@"d:\bigfile", @"\\192.168.10.2\bifgile");
contex.Undo();

but I get a System.Security.SecurityException "The name provided is not a properly formed account name."

So I tried

AppDomain.CurrentDomain.SetPrincipalPolicy(System.Security.Principal.PrincipalPolicy.WindowsPrincipal);
WindowsIdentity webinfinty = new WindowsIdentity("ComputerB\\UserB", "PasswordB"); //Execption

But I get "Logon failure: unknown user name or bad password." error instead.

so then I tried

IntPtr token;
bool succeded = LogonUser("UserB", "192.168.10.2", "PasswordB", LogonTypes.Network, LogonProviders.Default, out token);
if (!succeded)
{
     throw new Win32Exception(Marshal.GetLastWin32Error());
}
WindowsImpersonationContext contex = WindowsIdentity.Impersonate(token);
(...)
[DllImport("advapi32.dll", SetLastError = true)]
static extern bool LogonUser(
      string principal,
      string authority,
      string password,
      LogonTypes logonType,
      LogonProviders logonProvider,
      out IntPtr token);

but LogonUser returns false with the win32 error "Logon failure: unknown user name or bad password"

I know my username and password are fine, I have logged on to computerB as that user.

Any reccomandations