The Clip wasn’t really built for 64GB cards, because they use a different format from FAT32. It came out before they existed.
Was this exact same card working before you lent it? Maybe your friend’s computer did something to its formatting information.
Windows may not like it, but there are programs that will format it to FAT32. I Googled around and saw this thread.
which uses this program
Double and triple-check to make sure you are formatting the card and not some other drive. There are step-by-step instructions in the forum thread linked above. But be careful: Partitioning software is powerful, and if you apply it to the wrong drive you can mess up your computer badly.
In fact, I’d suggest setting a Restore Point (look in your Help files if you need instructions on how to do that) before running the program.