var unc = new UNCAccess(clientpath, System.Configuration.ConfigurationManager.AppSettings["login"], "", System.Configuration.ConfigurationManager.AppSettings["password"]);


//  access your file system here


    unc.NetUseDelete();

using System;
using System.Runtime.InteropServices;
using BOOL = System.Boolean;
using DWORD = System.UInt32;
using LPWSTR = System.String;
using NET_API_STATUS = System.UInt32;


public class UNCAccess
{
    [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
    internal struct USE_INFO_2
    {
        internal LPWSTR ui2_local;
        internal LPWSTR ui2_remote;
        internal LPWSTR ui2_password;
        internal DWORD ui2_status;
        internal DWORD ui2_asg_type;
        internal DWORD ui2_refcount;
        internal DWORD ui2_usecount;
        internal LPWSTR ui2_username;
        internal LPWSTR ui2_domainname;
    }

    [DllImport("NetApi32.dll", SetLastError = true, CharSet = CharSet.Unicode)]
    internal static extern NET_API_STATUS NetUseAdd(
        LPWSTR UncServerName,
        DWORD Level,
        ref USE_INFO_2 Buf,
        out DWORD ParmError);

    [DllImport("NetApi32.dll", SetLastError = true, CharSet = CharSet.Unicode)]
    internal static extern NET_API_STATUS NetUseDel(
        LPWSTR UncServerName,
        LPWSTR UseName,
        DWORD ForceCond);

    private string sUNCPath;
    private string sUser;
    private string sPassword;
    private string sDomain;
    private int iLastError;
    public UNCAccess()
    {
    }
    public UNCAccess(string UNCPath, string User, string Domain, string Password)
    {
        login(UNCPath, User, Domain, Password);
    }
    public int LastError
    {
        get { return iLastError; }
    }

    /// <summary>
    /// Connects to a UNC share folder with credentials
    /// </summary>
    /// <param name="UNCPath">UNC share path</param>
    /// <param name="User">Username</param>
    /// <param name="Domain">Domain</param>
    /// <param name="Password">Password</param>
    /// <returns>True if login was successful</returns>
    public bool login(string UNCPath, string User, string Domain, string Password)
    {
        sUNCPath = UNCPath;
        sUser = User;
        sPassword = Password;
        sDomain = Domain;
        return NetUseWithCredentials();
    }
    private bool NetUseWithCredentials()
    {
        uint returncode;
        try
        {
            USE_INFO_2 useinfo = new USE_INFO_2();

            useinfo.ui2_remote = sUNCPath;
            useinfo.ui2_username = sUser;
            useinfo.ui2_domainname = sDomain;
            useinfo.ui2_password = sPassword;
            useinfo.ui2_asg_type = 0;
            useinfo.ui2_usecount = 1;
            uint paramErrorIndex;
            returncode = NetUseAdd(null, 2, ref useinfo, out paramErrorIndex);
            iLastError = (int)returncode;
            return returncode == 0;
        }
        catch
        {
            iLastError = Marshal.GetLastWin32Error();
            return false;
        }
    }

    /// <summary>
    /// Closes the UNC share
    /// </summary>
    /// <returns>True if closing was successful</returns>
    public bool NetUseDelete()
    {
        uint returncode;
        try
        {
            returncode = NetUseDel(null, sUNCPath, 2);
            iLastError = (int)returncode;
            return (returncode == 0);
        }
        catch
        {
            iLastError = Marshal.GetLastWin32Error();
            return false;
        }
    }

}