Hard and Soft Write errors on Tapes

Soft write errors:

Soft write errors are the number of recoverable non-critical write errors that are encountered, meaning that a write operation on a block first failed and the subsequent retry was successful. If soft write errors are seen, it may indicate the beginning of a problem. When more of these soft write errors are seen, then you should consider checking the media for damage and cleaning the device, which will usually improve the situation. If the errors start to become excessive, the device may require servicing or replacing. As soft write errors usually indicate driver problems, check out the SCSI controller and device drivers, as approximately 95% of hardware errors and I/O errors are caused by outdated drivers.

Hard write errors:

Hard write errors are unrecoverable critical write errors that the tape device encounters, meaning that a write operation on a block failed and the subsequent retries also failed. This is generally a sign of problems with the tape device itself or possible problems with the SCSI configuration settings.  

Also in windows event viewer check for events like 5,7,9,11,15 for hardware failure.