I have a WB 3TB external harddrive. For some unknown reason Windows 7 will no longer let me access the drive until I format it. I get an error "_ You need to format the disk drive F: before you can use it." _ It says: _ “F:\ is not accessible. The volume does not contain a recognized file system. Please make sure that all the required system drivers are loaded and the volume is not corrupt.” _ My problem is I have been using the drive for several weeks and have data on this drive. Any ideas how to fix this? Please help.