Rather than using Office Interop, use a library which creates an Excel file directly. That way, it doesn't matter which version of Office your users have installed - your code will still work if they don't have Office installed at all.
Previously I would have recommended
EPPlus[
^]. However, the most up-to-date version is
no longer free for "commercial" use[
^]. If you don't meet the requirements for the free license, you would need to stick to v4, which is the last truly free version.
Other alternatives include
ClosedXML[
^],
NPOI[
^], or
The OpenXML SDK[
^].
Any of these will allow you to create an Excel spreadsheet on a machine which doesn't have Excel installed.