# Is there a way to make a thumb drive read only? **URL:** \ **Category:** Factual Questions\ **Created:** [June 19, 2012, 8:09pm UTC](https://boards.straightdope.com/t/is-there-a-way-to-make-a-thumb-drive-read-only/625676 "2012-06-19T20:09:48Z")\ **Posts on this page:** 13\ **Page:** 1
**Author:** ![StarvingButStrong](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/starvingbutstrong/32/335_2.png) [@StarvingButStrong](https://boards.straightdope.com/u/StarvingButStrong)\ **Post date:** [June 19, 2012, 8:09pm UTC](https://boards.straightdope.com/t/is-there-a-way-to-make-a-thumb-drive-read-only/625676/1 "2012-06-19T20:09:48Z")
Um. That’s pretty much it. (I want to transfer some files via thumb drive and don’t want them accidentally overwritten.) ---
**Author:** ![Panurge](https://avatars.discourse-cdn.com/v4/letter/p/fbc32d/32.png) [@Panurge](https://boards.straightdope.com/u/Panurge)\ **Post date:** [June 19, 2012, 8:16pm UTC](https://boards.straightdope.com/t/is-there-a-way-to-make-a-thumb-drive-read-only/625676/2 "2012-06-19T20:16:37Z")
It should be possible. [See here.](http://www.raymond.cc/blog/disable-write-access-to-removable-storage-devices/) You used to be able to buy thumb drives with a small switch that would prevent writing on the drive. Many (all?) SD cards have that switch, so if you have a card reader in your computer you could use one of those. ---
**Author:** ![needscoffee](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/needscoffee/32/1076_2.png) [@needscoffee](https://boards.straightdope.com/u/needscoffee)\ **Post date:** [June 19, 2012, 9:19pm UTC](https://boards.straightdope.com/t/is-there-a-way-to-make-a-thumb-drive-read-only/625676/3 "2012-06-19T21:19:10Z")
All my thumb drives have a lock switch, but you have to look for it. ---
**Author:** ![si\_blakely](https://avatars.discourse-cdn.com/v4/letter/s/d9b06d/32.png) [@si\_blakely](https://boards.straightdope.com/u/si_blakely)\ **Post date:** [June 19, 2012, 9:21pm UTC](https://boards.straightdope.com/t/is-there-a-way-to-make-a-thumb-drive-read-only/625676/4 "2012-06-19T21:21:26Z")
If you do not have a switch, you can flag files as Read-Only in Explorer/Finder. Si ---
**Author:** ![AaronX](https://avatars.discourse-cdn.com/v4/letter/a/7bcc69/32.png) [@AaronX](https://boards.straightdope.com/u/AaronX)\ **Post date:** [June 20, 2012, 8:45am UTC](https://boards.straightdope.com/t/is-there-a-way-to-make-a-thumb-drive-read-only/625676/5 "2012-06-20T08:45:57Z")
The switch doesn’t really do anything but tell the computer not to write on it. I think the only methods available are through software. Hmm maybe if you made the thumb drive appear as a CD? That way the computer wouldn’t attempt to write to it. But that would make it harder to use. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [June 20, 2012, 1:23pm UTC](https://boards.straightdope.com/t/is-there-a-way-to-make-a-thumb-drive-read-only/625676/6 "2012-06-20T13:23:15Z")
> [@AaronX](#): > > The switch doesn’t really do anything but tell the computer not to write on it. Are you sure? It’s a physical switch connected to the controller circuitry in the device - although I’m sure it would be possible to implement this so that it merely informed the host that the device is non-writable, it must also be quite easy to implement in a way where the controller just refuses to accept any write instructions (and that seems more sensible, as it would work independently of the reliability of the host). ---
**Author:** ![AaronX](https://avatars.discourse-cdn.com/v4/letter/a/7bcc69/32.png) [@AaronX](https://boards.straightdope.com/u/AaronX)\ **Post date:** [June 20, 2012, 1:28pm UTC](https://boards.straightdope.com/t/is-there-a-way-to-make-a-thumb-drive-read-only/625676/7 "2012-06-20T13:28:19Z")
I haven’t taken one apart, but I remember hearing you could fix (SD or Memory Stick) write protect switches with cellophane tape, just like the switches on VHS/cassette tapes. [http://www.flickr.com/photos/124330160/2452663566/](http://www.flickr.com/photos/124330160/2452663566/) Might have the answer. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [June 20, 2012, 1:34pm UTC](https://boards.straightdope.com/t/is-there-a-way-to-make-a-thumb-drive-read-only/625676/8 "2012-06-20T13:34:35Z")
On further investigation, it appears that the switch on USB thumb drives is generally implemented in hardware (so you can’t force an overwrite, no matter), whereas for SD cards, it’s a flag to the driver/OS to request that the volume be treated as read only, so in theory, it could be circumvented, although I guess that would mean writing/using a custom driver or something. ---
**Author:** ![AaronX](https://avatars.discourse-cdn.com/v4/letter/a/7bcc69/32.png) [@AaronX](https://boards.straightdope.com/u/AaronX)\ **Post date:** [June 20, 2012, 1:46pm UTC](https://boards.straightdope.com/t/is-there-a-way-to-make-a-thumb-drive-read-only/625676/9 "2012-06-20T13:46:02Z")
Or you could break off the sensing tabs in the card reader. I’ve never heard of any switches on memory actually being electrically connected though. Which thumb drives have those? ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [June 20, 2012, 2:34pm UTC](https://boards.straightdope.com/t/is-there-a-way-to-make-a-thumb-drive-read-only/625676/10 "2012-06-20T14:34:08Z")
> [@AaronX](#): > > I’ve never heard of any switches on memory actually being electrically connected though. Which thumb drives have those? Not many these days, but any USB thumb drive that has a switch will have it implemented in hardware (reason being: with SD cards, the ‘switch’ actually goes inside the reader, where a sensor can see it. With USB devices, they just plug into a standard USB port, which is not equipped to do anything other than connect the terminals - the switch stays outside on the device). Here’s an example of the internals of a US drive with a write protect switch: > **[카지노사이트 정보에 대한 모든것 - sectechno](https://www.sectechno.com)** > > 카지노사이트 정보에 대한 모든것카지노사이트 정보를 알려드리겠습니다. 현대 사회에서 빠르게 성장하고 있는 온라인 도박 산업의 핵심입니다. 이 기사에서는 카지노사이트에 대한 모든 정보를 다루며, 온라인 도박의 변화와 흥미로운 측면을 탐구하고자 합니다. ---
**Author:** ![si\_blakely](https://avatars.discourse-cdn.com/v4/letter/s/d9b06d/32.png) [@si\_blakely](https://boards.straightdope.com/u/si_blakely)\ **Post date:** [June 20, 2012, 2:35pm UTC](https://boards.straightdope.com/t/is-there-a-way-to-make-a-thumb-drive-read-only/625676/11 "2012-06-20T14:35:18Z")
> [@AaronX](#): > > Or you could break off the sensing tabs in the card reader. > > I’ve never heard of any switches on memory actually being electrically connected though. Which thumb drives have those? Some USB Flash Drives have hardware Read-Only switches - here is a [list](http://www.fencepost.net/2010/03/usb-flash-drives-with-hardware-write-protection/) of some that are available in the US, and it looks pretty current. It also appears that manufacturers are not producing as many USB drives with this functionality. Si ---
**Author:** ![StarvingButStrong](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/starvingbutstrong/32/335_2.png) [@StarvingButStrong](https://boards.straightdope.com/u/StarvingButStrong)\ **Post date:** [June 20, 2012, 3:31pm UTC](https://boards.straightdope.com/t/is-there-a-way-to-make-a-thumb-drive-read-only/625676/12 "2012-06-20T15:31:46Z")
Well, I’ve just inspected the eight thumbdrives I have on hand, and none of them have any sort of physical switch visible. So off to buy another. Thanks for the list, Si! ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [June 20, 2012, 5:01pm UTC](https://boards.straightdope.com/t/is-there-a-way-to-make-a-thumb-drive-read-only/625676/13 "2012-06-20T17:01:36Z")
It’s possible that some of your devices have PCB tracks for a switch, but no switch. If any of them happen to be easy to pop open, it might be worth a look inside.