Welcome, saravana_3!
Can you please provide more details about your system and your hard drive? I'd suggest you go to
Disk Management in Windows and check how it appears there. If you could also share some links to screenshots, it would be really helpful.
Another thing you could try is access your hard drive contents from another computer. I'd also try to switch the power supply that is connecting the HDD to your computer. If it's an external drive, try a different USB cable. If it's an internal drive, attempt to plug it with a different SATA cable.
Give some more details, so we could be more helpful.
SuperSoph_WD