The likely cause of the apparent disappearance of bookmarks since an upgrade to Windows 10 is that the browser you are now using is Microsoft Edge, this is the new browser from Microsoft.
To import your bookmarks,
1. Click the ellipsis menu (3 dots) in the top right
2. Click on Settings
3. Click on the button to import from another browser
4. Choose Internet Explorer
5. Click import
Your bookmarks will be imported from IE.