I've recently upgraded my computer to Windows 10 from Windows 7, but My WIFI Router doesn't work anymore. Should I just reinstall it? Or should I look elsewhere for a laptop hotspot?
At this moment My WIFI Router is not yet available for Windows 10 and reinstalling the software won't help you. If you are in an urgent need to turn your laptop into a hotspot you can try another application available through the database of Software Informer which at this date is Windows 10 compatible: http://connectify-hotspot.software.informer.com/download/
If your Windows 7 computer has wireless network card, you can directly create WiFi hotspot on your computer. And the process is easy, as long as you have hotspot tool.