What is your definition of “importing PDF files”. Taking a PDF and “importing” into Endnote, so that the metadata create a record wasn’t implimented until EndnoteX4 I think. So does your professor have X4 and you have X3 on your PC?
copying a pdf onto an existing record should work. If the record is open, drag it onto the record. If the library view is open, drag it onto the line where the record it matches is.
otherwise, again if you have downloaded the record via the connect functions (recommend switching to the third mode button in the upper left of the library window to avoid retrieving all matches into your library. then you need to right click on the record you want and copy to the main library).
How are you retrieving the enw file. and What browser are you using? And do you have the RIS filter available? On Windows if you are asked to choose which program to use to open the file you could try browsing to: C:\Program Files\Common Files\Risxtd\Risweb32.exe
Did you try to associate the .enw file with Endnote? Try a different browser and it may request the program. See this thread.
And then to retrieve the pdf for a record, also try “find full text” after selecting the
Google Chrome lists the file at the bottom of the window and when I click it (the equivalent of “open” option in other browsers) it opens Endnote and adds the reference to the default library. Chrome too gives you a drop-down list which offers to remember to automatically open this file type in future.
You want it to be trying to open it with Endnote. You can check whether your filters includes the Refman RIS filter - I can’t test things since I don’t have X3 on my machine. You can also try saving the file and importing it from Endnote, which may work better for you?