My problem comes when trying to transfer files from my HP Laptop, running Windows 7 Professional, to my phone - or more specifically to the MicroSD card.
The Android OS allows me to specify that the MicroSD card should be treated by other devices as a USB drive. After a couple of attempts (I had to tell the phone to "mount" and "format" the card), both the phone's internal storage and the MicroSD card show up as drives in Windows 7 Explorer when the phone is attached to the laptop.
So far, so good.
I had hoped to use the MicroSD for music. I am finding that while I can move certain types of files to the microSD(jpg seems to work OK, haven't tried others), if I try to move music files (mp3 or wma, format doesn't matter) I inevitably get an error "Cannot read from source file or disk". I have tried using backed-up versions of the files and I get the same error. I tried moving the same song files to a USB flash drive and had no problem. This is why i posted the issue on an Android forum : I think it must be a an OS issue. Or possibly it's an issue with the microSD card. I had no problem moving the song files to the phone's internal storage.