Excel is not installed on your server.
Additionally, using Office automation from non-interactive applications (eg: websites) is not supported:
Microsoft does not currently recommend, and does not support, Automation of Microsoft Office applications from any unattended, non-interactive client application or component (including ASP, ASP.NET, DCOM, and NT Services), because Office may exhibit unstable behavior and/or deadlock when Office is run in this environment.
You'll need to use a different approach to read the files.
You might be able to get away with using ODBC:
Reading Excel files using ODBC[
^]
If your site only needs to support the newer file formats (
.xlsx
), then you could use
EPPlus[
^],
ClosedXML[
^], or
the OpenXML SDK[
^].
If you need to support older format files (
.xls
) as well, then you can use
NPOI[
^].