Error to load the ExcelDna64.xll

Nov 27, 2012 at 11:34 AM

I used 64-bit OS + Excel2010 +

I always get the error  ""ExcelDna64.xll" is not a valid add-in" when I Browse... and select the ExcelDna64.xll in excel.

Please help me.

Nov 27, 2012 at 11:53 AM


The choice of whether to use the 32-bit ExcelDna.xll or the 64-bit ExcelDna64.xll depends on your Excel version, and not on your Windows version. The default installation for Office 2010 on 64-bit Windows is still to install the 32-bit version of Office. You only have the 64-bit Office if you chose it explicitly.

So you probably need to use the ExcelDna.xll instead. Have you tried it?


Nov 28, 2012 at 8:39 AM

Thanks.  I think i installed the 32-bit version of Office. But I would like to call a 64-bit .dll(no 32-bit version) in the excel-DNA. How to fix it?

Nov 28, 2012 at 2:32 PM

Windows will not allow you to load a 64-bit library into a 32-bit Excel process.

The only way might be to create your own host process, and then use some inter-process communication to call into the other .dll.