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I would be glad to help. The issue you are having is often due to the type of file system that the drive is formatted with. If the format is exFAT or NTFS any version of Mac OS X is going to have trouble accessing the data on that drive. The only way to solve this without losing your data, would be to transfer the contents of the drive to another Windows drive, then format your drive using a more compatible file system like FAT32 and then put the contents back onto the drive.
I would be happy to walk you through the steps to do this. Do you have enough storage space on another drive on a Windows machine that you can do the transfer with?