Unable to access harddisk without formatting

[Atalaya]

Few months back i'm using 500 GB harddisk but now i've upgraded my pc with 1TB harddisk.Last few days i could not get access to the harddisk because it shows an error "need to be formatted". The files and data in my harddisk are very important and i don't want to lose them.Can i still get the files after formatting?.

[BansiJ]

I think your computer is not allowing to access your 2nd harddrive. Please check that the master drive is attached to the last connecter on the ribbon cable after checking that make sure that the jumper switch is set to MASTER(WITH SLAVE if available) on the master and (SLAVE) ON THE SLAVE.

[Antonio1]

The drive you could not getting access must having format FAT32, and other drive having NTFS.Both the format using different driver. There default location is C:\WINDOWS\system32\drivers\fastfat.sys
C:\WINDOWS\system32\drivers\ntfs.sys.To load the driver you have to change the file name to "fastfat_BACKUP.sys" then reboot the computer. once it rebooted you can gain access to all your harddisk.

[Carlos16]

I think, that filesystem is corrupted you must use recovery software to recover your data.There are many recovery software available online like Acronis Disc Director. Another option is try to run HD Tune Error check to check hdd. if it nothing found than your harddisk is OK. If this does'nt work go to a h/w engineer or technician.