On the W7 machine open Firefox and press Ctrl, Shift and B together.
Click on 'Import &Backup' (at the top of the page).
Select 'Export Bookmarks to HTML'
Save your bookmarks file to a USB pen drive. (Alternatively save it to your hard drive and email it to yourself, so that you can access it from your W10 machine).
On your W10 machine, ensure that you've got the bookmarks file handy (either on the USB stick you saved it to or downloaded from your email onto your hard drive).
Install Firefox (
https://www.mozilla.org/en-GB/firefox/new/ ), open it, press Ctrl-Shift-B, go to 'Import & Backup' and select 'Import Bookmarks from HTML'. Then navigate to the file location and double-click on it (or single-click and hit 'Open').
If you want to use Edge you'll find that, annoyingly, you can't import them directly from the HTML file that you've saved. (Typical Microsoft - leaving out something which obviously needs to be there!). Instead you need to import them into another browser first (which is why I said that you should install Firefox, even if you've no intention of using it).
Once you've installed Firefox and imported your bookmarks to it, open Edge and click the Menu button (three dots).
Click 'Settings' and then on 'Import Favorites from Another Browser'.
Put a tick next to 'Firefox' and click 'Import'.