iPhone Restoration Issue using Windows PC

I was trying to unlock my relative's phone and was confident since I unlocked an Ipad before in the same situation when it gets disabled due to forgotten password. But this time, I tried it with the same computer (windows). When I try to restore phone through apple devices app, nothing happens after I clicked "Restore iPhone" and there's no option to "Check for Update." I switched to iTunes, when I was trying to update the phone through iTunes first, it told me there's an error, I restarted my pc and checked that my iTunes is the most recent updated version. Then I tried again, still the same result. Next, I tried to start over but click "Restore phone" and "Restore and Update" instead of "Update." iTunes then sent the phone into updating mode but then the iTunes window on my pc closed out and the progress bar appears the same (about 5% completed) even after I waited a few hours.

I repeated these procedures a lot of times and seek out for different ways but nothing works and they all yield the same results.

Plus, I wanted to go back to the home screen just to check but it kept staying in recovery mode even after I force restarted it.

Please help.

[Re-Titled By Moderator]