Hi there Kittyanne,
Either the enclosure has failed or the cable is bad.
You can start with just changing the USB cable. Trying the drive on another port/system will not hurt as well. In case the issue persists, I guess you have several options:
- RMA the drive in case it is under warranty.
- In case the data stored on it is really important, you may need to contact a data recovery company.
- In similar cases, some users take the drive out of the enclosure and connect it internally. Though, keep in mind that this will void the warranty and may not work in case the drive has some proprietary connectors.
Cheers,
D_Know_WD