| If you need... | Best action | |----------------|--------------| | | Install Office 2007 (if you have a license) or use a virtual machine with it. | | Any Excel automation | Use a modern Office version (365/2019/2016) and reference version 16.0. Change your code’s version GUID if necessary (usually not required). | | No Office installed | Consider Open XML SDK (for file manipulation without Excel) or EPPlus / ClosedXML (3rd-party libraries, no Office required). |