This isn't a problem I've experienced with pdf's, but one way around it could be to use Dropbox. You have the App on the Nook and the program on your pc, and you can drag and drop files to the Dropbox cloud and they are also available on your Nook.
Dropbox is free.
Hope you manage to resolve this.
Are you using the most recent version of WMP? In Android 4, the Nook internal and external storage are treated as media devices and require the latest version (11, i think). I have had no problems transferring PDFs or other files using Windows 7 or 8. In addition to Dropbox (and other cloud storage options) noted above, file manager apps such as Open Explorer (Nook and GoPS) and ES and others in the GoPS permit wireless transfers between the Nook and PCs - managed from the Nook rather than the PC whic won't see the Nook.
Can you give us some more info about just what you are doing?
Since your are on the HD/HD+ forum, it is an assumption on our part what Nook you have. Can you be specific?
Are you using a PC or Mac?
What OS if your are using a PC, XP, Vista, 7, or 8?
What happens when you initially attach your Nook to your computer? Does a Windows Explorer box pop up asking how you want to look at those files? Can you see the file content of your Nook on your computer screen?
I find the easiest way to transfer files is to:
1) Connect HD to my PC (Windows 7)
2) Open Windows Explorer. (looks like a file in the bottom tray)
3) find the file on my PC that I wish to copy.
4) select file
5)click on Edit in the tool bar and select "copy to folder)
6) from the provided list, select BVNT400\sdcard\My Files\.....
Hope this helps
I just bought my NOOK a month ago and now I am still trying to learn to use it. One thing I just found is that I cannot copy files from computer and paste it in microSD on NOOK while connecting my NOOK using a USB cable. In fact, neither can I copy files from computer and paste them in NOOK's internal storage. There is a pop-up warning saying that the file is not supported and asking me to convert PDF files using window media player. I do not think I can convert PDF files using windows media player.
Such a problem can be partially solved by taking microSD card out from NOOK and plug it into my SD card reader on the computer using an microSD adapter. However, it is a great hassel for me to that every time I want to copy files from my computer to NOOK. Do you guys have similar problem? Can you figure out a way of copying files from computer to NOOK HD+ using USB cable instead of a microSD adapter?
Thank you so much.
Suggest you just ignore the warning and let the file copy. Iget the warning too with certain file types, but they always successfully copy. It's a standard warning that Windows gives for when the media transfer protocol (MTP) is used, which is how the HD+ communicates with Windows.