Hopefully! it will be helpful for you. :)

  public static class FileInfoExtensions
    {
        /// <summary>
        /// behavior when new filename is exist.
        /// </summary>
        public enum FileExistBehavior
        {
            /// <summary>
            /// None: throw IOException "The destination file already exists."
            /// </summary>
            None = 0,
            /// <summary>
            /// Replace: replace the file in the destination.
            /// </summary>
            Replace = 1,
            /// <summary>
            /// Skip: skip this file.
            /// </summary>
            Skip = 2,
            /// <summary>
            /// Rename: rename the file. (like a window behavior)
            /// </summary>
            Rename = 3
        }
        /// <summary>
        /// Rename the file.
        /// </summary>
        /// <param name="fileInfo">the target file.</param>
        /// <param name="newFileName">new filename with extension.</param>
        /// <param name="fileExistBehavior">behavior when new filename is exist.</param>
        public static void Rename(this System.IO.FileInfo fileInfo, string newFileName, FileExistBehavior fileExistBehavior = FileExistBehavior.None)
        {
            string newFileNameWithoutExtension = System.IO.Path.GetFileNameWithoutExtension(newFileName);
            string newFileNameExtension = System.IO.Path.GetExtension(newFileName);
            string newFilePath = System.IO.Path.Combine(fileInfo.Directory.FullName, newFileName);

            if (System.IO.File.Exists(newFilePath))
            {
                switch (fileExistBehavior)
                {
                    case FileExistBehavior.None:
                        throw new System.IO.IOException("The destination file already exists.");
                    case FileExistBehavior.Replace:
                        System.IO.File.Delete(newFilePath);
                        break;
                    case FileExistBehavior.Rename:
                        int dupplicate_count = 0;
                        string newFileNameWithDupplicateIndex;
                        string newFilePathWithDupplicateIndex;
                        do
                        {
                            dupplicate_count++;
                            newFileNameWithDupplicateIndex = newFileNameWithoutExtension + " (" + dupplicate_count + ")" + newFileNameExtension;
                            newFilePathWithDupplicateIndex = System.IO.Path.Combine(fileInfo.Directory.FullName, newFileNameWithDupplicateIndex);
                        } while (System.IO.File.Exists(newFilePathWithDupplicateIndex));
                        newFilePath = newFilePathWithDupplicateIndex;
                        break;
                    case FileExistBehavior.Skip:
                        return;
                }
            }
            System.IO.File.Move(fileInfo.FullName, newFilePath);
        }
    }

How to use this code ?

class Program
    {
        static void Main(string[] args)
        {
            string targetFile = System.IO.Path.Combine(@"D://test", "New Text Document.txt");
            string newFileName = "Foo.txt";

            // full pattern
            System.IO.FileInfo fileInfo = new System.IO.FileInfo(targetFile);
            fileInfo.Rename(newFileName);

            // or short form
            new System.IO.FileInfo(targetFile).Rename(newFileName);
        }
    }

Use:

public static class FileInfoExtensions
{
    /// <summary>
    /// Behavior when a new filename exists.
    /// </summary>
    public enum FileExistBehavior
    {
        /// <summary>
        /// None: throw IOException "The destination file already exists."
        /// </summary>
        None = 0,
        /// <summary>
        /// Replace: replace the file in the destination.
        /// </summary>
        Replace = 1,
        /// <summary>
        /// Skip: skip this file.
        /// </summary>
        Skip = 2,
        /// <summary>
        /// Rename: rename the file (like a window behavior)
        /// </summary>
        Rename = 3
    }
 

    /// <summary>
    /// Rename the file.
    /// </summary>
    /// <param name="fileInfo">the target file.</param>
    /// <param name="newFileName">new filename with extension.</param>
    /// <param name="fileExistBehavior">behavior when new filename is exist.</param>
    public static void Rename(this System.IO.FileInfo fileInfo, string newFileName, FileExistBehavior fileExistBehavior = FileExistBehavior.None)
    {
        string newFileNameWithoutExtension = System.IO.Path.GetFileNameWithoutExtension(newFileName);
        string newFileNameExtension = System.IO.Path.GetExtension(newFileName);
        string newFilePath = System.IO.Path.Combine(fileInfo.Directory.FullName, newFileName);

        if (System.IO.File.Exists(newFilePath))
        {
            switch (fileExistBehavior)
            {
                case FileExistBehavior.None:
                    throw new System.IO.IOException("The destination file already exists.");
 
                case FileExistBehavior.Replace:
                    System.IO.File.Delete(newFilePath);
                    break;
 
                case FileExistBehavior.Rename:
                    int dupplicate_count = 0;
                    string newFileNameWithDupplicateIndex;
                    string newFilePathWithDupplicateIndex;
                    do
                    {
                        dupplicate_count++;
                        newFileNameWithDupplicateIndex = newFileNameWithoutExtension + " (" + dupplicate_count + ")" + newFileNameExtension;
                        newFilePathWithDupplicateIndex = System.IO.Path.Combine(fileInfo.Directory.FullName, newFileNameWithDupplicateIndex);
                    }
                    while (System.IO.File.Exists(newFilePathWithDupplicateIndex));
 
                    newFilePath = newFilePathWithDupplicateIndex;
                    break;
 
                case FileExistBehavior.Skip:
                    return;
            }
        }
        System.IO.File.Move(fileInfo.FullName, newFilePath);
    }
}

How to use this code

class Program
{
    static void Main(string[] args)
    {
        string targetFile = System.IO.Path.Combine(@"D://test", "New Text Document.txt");
        string newFileName = "Foo.txt";

        // Full pattern
        System.IO.FileInfo fileInfo = new System.IO.FileInfo(targetFile);
        fileInfo.Rename(newFileName);

        // Or short form
        new System.IO.FileInfo(targetFile).Rename(newFileName);
    }
}