How to create Excel (.XLS and .XLSX) file in C# without installing Ms Office ?

Here, ExcelLibrary. It is a free, open source library:

    This look to be a port of the PHP ExcelWriter that may mentioned above. It will not write to the new .xlsx format yet, but they are working on adding that functionality in.

It is  easy to use. Plus it has a DataSetHelper that lets you use DataSets and DataTables to easily work with Excel data.

There are a few known bugs with each library as noted in the comments. In all, EPPlus seems to be the best choice as time goes on. It seems to be more actively updated and documented as well.

EPPlus has support for Pivot Tables and ExcelLibrary may have some support.

Here are a couple links for quick reference:

ExcelLibrary – GNU Lesser GP

Just you can try this code for ExcelLibrary:

//Create the data set and table
DataSet ds = new DataSet("New_DataSet");
DataTable dt = new DataTable("New_DataTable");
 
//Set the locale for each
ds.Locale = System.Threading.Thread.CurrentThread.CurrentCulture;
dt.Locale = System.Threading.Thread.CurrentThread.CurrentCulture;
 
//Open a DB connection (in this example with OleDB)
OleDbConnection con = new OleDbConnection(dbConnectionString);
con.Open();
 
//Create a query and fill the data table with the data from the DB
string sql = "SELECT Whatever FROM MyDBTable;";
OleDbCommand cmd = new OleDbCommand(sql, con);
OleDbDataAdapter adptr = new OleDbDataAdapter();
 
adptr.SelectCommand = cmd;
adptr.Fill(dt);
con.Close();
 
//Add the table to the data set
ds.Tables.Add(dt);
 
//Here's the easy part. Create the Excel worksheet from the data set
ExcelLibrary.DataSetHelper.CreateWorkbook("MyExcelFile.xls", ds);

Your solution is here,

    Use this codeplex GitHub project. EPPlus. Started it with the source from ExcelPackage, but today it is a total rewrite. Supports ranges, cell styling, charts, shapes, pictures, namesranges, autofilter and a lot of other stuff.

Follow this answer,

Can use this with success the following open source projects:

• ExcelPackage for OOXML formats (Office 2007)
• NPOI for .XLS format (Office 2003). NPOI 2.0 (Alpha) also supports XLSX.