Dear Martin Marinkov,
Good day! Thank you for posting in our community. Your question is "MS Forms - location of attached files". Here are the answers to your questions.
1) Where will these images/photos be stored ?
For personal forms, it is stored on your OneDrive site.
For group forms, it is stored on your SharePoint site.
To see the detail location, you can go to Response page >> View result >> Find any answer which contains the attachments, click it >> it should be open from Online >> From the URL, you can see its location. For example, my file URL is https://domain-my.sharepoint.com/personal/username_com/Documents/Apps/Microsoft%20Forms/Untitled%20form%20Question/PictureName.png
From the URL, we can tell it is stored on my OneDrive site, Apps folder >> Microsoft Forms folder >> Untitled form question folder.
2) Can I change the location where they are stored ?
No, you are not able to change it from Forms. Even though you are able to manually move it from your OneDrive or SharePoint site, we do not suggest you doing that. It will easily cause Forms crashing or other problems.
3) Are there any limits to the total amount of gigabytes that can be uploaded (or am I only limited by the capacity of the storage location specified by me) ?
When adding the "upload files" question type, you are required to enter the limitations of the attachments. See below picture for the max of attachment limits. Besides that, it is also limited by your OneDrive or SharePoint site storage. When the site storage is full, user will fail to upload attachments.
Thank you for your cooperation and have a nice day!
Best Regards,
