External Drive Lights, but not getting detected

My Passport is not detected though It lights up. The message on the computer screen is - fomat for use. I will lose data, if I format it. How to format without losing data.

Hi,

A steady power led light on the WD My Passport drive signify that the hard drive is getting power but it is in idle state. It would blink fast while data transfer.

‘Format the drive’ message is most probable to occur if your external hard disk has been corrupted. You could use third party data recovery tools mentioned in the link provided below to recover the data from it.