Windows 10: changed access to external hard drive

I made a mistake by changing something I should not.
My system is dutch so I must translate, which is probably not always clear, sorry for that.
Here is what happened:
I opened filebrowser and I saw a little icon with two heads under my external hard drive. I thought that has something to do with sharing. I right clicked on this external hard drive and chose 'sharing with'.
Then on 'advanced sharing' and a new window opened.
I choose the label 'security' and there I saw three user groups to have acces to my hard drive. The first was EVERYBODY (or everyone) which surprised me so I changed it. Now I do not have acces to my harddrive at all and I can not change it back either. It says 'you should have reading permission to see the properties of this object', (or so).
Can anybody guide me through the process to reverse my misstake?
looking for a sollution I found out that I never enabled the possibillity to restore the last systemchange. Well they say one learns from ones mistakes.

:)

 

External hard drive changed to esd-usb

While performing window media creation I have converted my external hard drive as bootable usb device (esd-usb). I couldn't recover my files in the hard drive . Need help

 

External hard drive changed to esd-usb

I'm Greg, a volunteer installation specialist and 8 year Windows MVP, here to help you.

Did you notice the Warning box that said which drive was about to be formatted over to create the media?

I'm afraid that once a drive is formatted over there is no way to recover the files since it will have used the first 32gb and that contains the partition table that would need to be used to piece back together data existing on the rest of the drive.

There are professional data recovery services but they are expensive. You can also try with an app like Recuva just to be sure:
Recuva - Features

This is a major problem which Microsoft has been notified about repeatedly. To add your voice please go to the Feedback Hub in Start menu to search for and vote up the issue, or create a new Feedback on it. You can even use the Share button in the completed
feedback to post a link back here so others can vote it up for you and add their voice.

In the future I suggest intstalling Google drive's new Backup feature which lets you designate User and other folders to sync in real time up to 15gb free to the Google Cloud where they can be accessed and restored from the internet. This gives a secondary
backup that's available to you from any device.

I hope this helps. Feel free to ask back any questions and let us know how it goes. I will keep working with you until it's resolved.