Cannot open any site correctly with Tor

It’s completely up to you, but I myself would not use a device that I believed to be compromised by malicious software or the like. But this issue might not be related to malware.

It leads me to believe that the issue is with your OS’ software or configuration. You are running Windows 8.1, quite an old OS with very few users, so I think very few TB users/developers have actually tested TB against that OS. Do you have any chance of upgrading to Windows 10? If not, and you really would like to use TB on your device, you could wipe it and re-install Windows 8.1 to see if that fixes the issue. But maybe you’ve already considered this.

I have no choice but to continue with the same device for now. I will consider upgrading OS but Linux would be preferable.