Hello everyone! This is my first post here but I've been watching since the old days. I have some PC's that I use for mining and I control them through TeamViewer. Sometimes one or more of PCs freeze and I have to go and restart them manually. Is there a way that doesn't cost hundreds of dollars for me to remotely restart my computers? I really don't have the time to go and restart them manually. Thanks!
If I were you, I would not so much look for a workaround for hanging machines, but rather trying to fix the issue 
I have a Windows machine running at home (that I access via RDP) that runs for months without hiccups (occasional restart for Updates ofc), so there seems to be a problem with your installation.
Nevertheless if you really need it, you could also look into you configuration. On most mainboards there's a watchdog timer and you can configure the system in a way that it restarts automatically when the system hangs for a certain amount of time.
There are also some ideas here:
I assume they do not have IPMI chip that would allow for that (some workstation motherboards might have it or have a slot for it)...
One day I came up with the IDEA of setting in UEFI/BIOS my two PCs to "Power-ON state on power failure" and connect power cables via PDU. The problem was to find a cheap PDU.
Could use a WEMO switch or similar. Set the BIOS to restart after power failure and just toggle the AC power?
The problem with switching power on/off is when it happens too often it can kill a cheap PSU real quick. Higher quality PSUs are usually no problem, though it's not exactly recommended either.
I did something similar for my home server in order to have it turn on after a power outage in a controlled way. I wired a relay in parallel to its power button and set up a Raspberry Pi to control the relay through GPIO.
Use a Raspberry Pi or any other small, cheap Linux computer with GPIO to control relays wired to the power/reset pins on your mobos. You could then ssh into the Pi and just "press the button" using the relays. You could also do this with no relays at all and just using transistors in parallel with the power button, but I went with a relay because I didn't want to electrically connect the RasPi to the server's mobo, it felt "safer" I guess.
Neat Idea!
If you don't have a Rpi you could use a WEMO Maker