What version of OfficeWriter do I need for 64-bit support? Full 64-bit support for OfficeWriter's pure .NET classes was introduced in OfficeWriter 3.9.1 (ExcelWriter 6.9.1). The OfficeWriter .NET dlls are compiled with the /anycpu flag so they will work fine on either 32-bit or 64-bit systems. OfficeWriter's COM dlls are still 32-bit. If you have ... Continue reading Using OfficeWriter .NET on a 64-bit machine →