Do not format your drive or you will loose your data on it.
If your program "DDR professional recovery - demo version" cannot access the files on your HD then try using this free program TESTDISK 6.11.3
download here: http://www.cgsecurit...stDisk_Download
Description of the program:
TestDisk is a powerful free data recovery software! It was primarily designed to help recover lost partitions and/or make non-booting disks bootable again when these symptoms are caused by faulty software, certain types of viruses or human error (such as accidentally deleting a Partition Table). Partition table recovery using TestDisk is really easy.
Fix partition table, recover deleted partition
Recover FAT32 boot sector from its backup
Rebuild FAT12/FAT16/FAT32 boot sector
Fix FAT tables
Rebuild NTFS boot sector
Recover NTFS boot sector from its backup
Fix MFT using MFT mirror
Locate ext2/ext3 Backup SuperBlock
Undelete files from FAT, NTFS and ext2 filesystem
Copy files from deleted FAT, NTFS and ext2/ext3 partitions.
TestDisk has features for both novices and experts. For those who know little or nothing about data recovery techniques, TestDisk can be used to collect detailed information about a non-booting drive which can then be sent to a tech for further analysis. Those more familiar with such procedures should find TestDisk a handy tool in performing onsite recovery.
With this tool you can recover your data on your HD and once it is recovered and copied to another HD or partition you can then format your unformated partition or HD.