# Duplicating an SD card which has data which can't be seen by Window 10 File Explorer

**URL:** <https://forums.balena.io/t/duplicating-an-sd-card-which-has-data-which-cant-be-seen-by-window-10-file-explorer/317571>\
**Category:** balenaEtcher\
**Created:** [May 17, 2021, 7:02pm UTC](https://forums.balena.io/t/duplicating-an-sd-card-which-has-data-which-cant-be-seen-by-window-10-file-explorer/317571 "2021-05-17T19:02:16Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![machare](https://avatars.discourse-cdn.com/v4/letter/m/7cd45c/32.png) [@machare](https://forums.balena.io/u/machare)\
**Post date:** [May 17, 2021, 7:02pm UTC](https://forums.balena.io/t/duplicating-an-sd-card-which-has-data-which-cant-be-seen-by-window-10-file-explorer/317571/1 "2021-05-17T19:02:16Z")

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When copy from one SD card to another does balenaEtcher do a sector by sector copy regardless of what is held in the sector of does it format the new card and then copy the files as Windows 10 or Linux might?

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**Author:** ![dtischler](https://sea2.discourse-cdn.com/balena/user_avatar/forums.balena.io/dtischler/32/2483_2.png) [@dtischler](https://forums.balena.io/u/dtischler)\
**Post date:** [May 21, 2021, 11:11pm UTC](https://forums.balena.io/t/duplicating-an-sd-card-which-has-data-which-cant-be-seen-by-window-10-file-explorer/317571/6 "2021-05-21T23:11:06Z")

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Hi there @machare – You are correct, it simply copies block-by-block, without knowing what is actually in the block. It does perform a format of the drive, and then copy in files directly. Hope that helps, thanks.