Yes, you would have to install Office, to get Office interop assemblies. When Office is installed, those assemblies go to GAC, so you would add a reference by using the tab ".NET" of the Visual Studio "Add Reference" window. And of course, the user's computer should also have Office installed.
This can be unacceptable due to licensing limitations. Alternatively, you can use Open XML SDK:
http://www.microsoft.com/en-us/download/details.aspx?id=30425[
^].
This way, you can support new XML-based Office formats (such as .DOCX, .XLSX), ECMA-376 standard:
http://en.wikipedia.org/wiki/Microsoft_Office_XML_formats[
^],
http://en.wikipedia.org/wiki/Office_Open_XML[
^].
This way, you can work without Office installed. Also, the documents are supported by 3rd-party software. Please see my past answers:
Convert Office-Documents to PDF without interop[
^],
Need a rather unique WPF text editor control[
^],
Hi how can i display word file in windows application using c#.net[
^],
Read a word file without using Interop.word dll...Do not want to install word in IIS..[
^].
This is another option:
http://npoi.codeplex.com/[
^].
See also:
http://support.microsoft.com/default.aspx?scid=kb;EN-US;q257757#kb2[
^].
[EDIT]
See also this CodeProject article by Mika Wendelius:
Creating basic Excel workbook with Open XML[
^].
—SA