wipe data/factory reset and SD card data

Hi,

I have done the "wipe data/factory reset" on my samsung galaxy s3. After that, I found that all my files (including photos, videos, and pdf files) in external SD card are not opened by any software. It seems the "wipe data" affect to the files in external SD card. I transferred the files into my computer but still same. Anyone could help how can I restore or fix this?

Thank you in advance.:D

Petros