So you've reached that moment: the front USB ports on your case are not working. You replay the situation in your head over and over, but you can't recall any damaging action. Sometimes the symptoms appear as a long process of intermittent failures, and other times it happens overnight, ignoring every device you try to connect. Why does this happen? What can we do to fix it?
Inspect the port closely
No, it's not a joke. Sometimes the most common problem is the one we ignore first, and a bent, cut, or crushed pin in the USB port can ruin our day. Other common examples are HDMI ports, the USB-C port of the Nintendo Switch (which ends up reduced to dust when an overly intense user connects the console to its dock), and the Micro USB ports on every smartphone and tablet out there. With physical damage identified, our next step is to look for a replacement, but if the port looks fine, then...
Confirm the device works
Unfortunately, my long list of dead pen drives and adapters forces me to explore this possibility. Sometimes the fault is not the port, but what we are trying to connect. Hundreds of cycles on a connector plus cheap generic Chinese cables of dubious quality form a perfect storm that always ends in silence... because the computer doesn't detect anything. The easiest thing is to test the device on another port (say, the ones connected to the motherboard on the back), or directly on another computer.
Is everything connected properly inside...?
I admit it: it can happen. Every computer needs a cleaning from time to time, and many users decide to follow the full teardown route, and the cable for the front USB ports gets forgotten in a corner, or half-connected to the motherboard. If you've done something like that recently, it's not a bad idea to review all internal connections. Remember that there are three different types of USB headers on modern motherboards: standard USB 2.0, the soul torturer called USB 3.0, and the new USB 3.1 Gen2.
Front USB ports not working: What does Windows think?
It is supposed that at this point Windows should automatically detect and configure any USB port... but it's a big 'supposed to.' In practice, we can never rule out driver updates via Windows Update or changes in power policies that leave our USB ports out of action.
In those cases, our best strategy is to revert the installation of any driver, or on the contrary, go to the official page of Intel or AMD (depending on the platform you use) and get the latest controller for our motherboard's chipset, which should include updated USB modules.
It is also recommended to disable USB selective suspend in power plans, and turn off the option 'Allow the computer to turn off...' on the USB hubs detected by the device manager. With a bit of luck, the front USB ports will work without issues... but it's impossible to ignore a fundamental truth about them.
Front USB ports are (almost always) garbage
You are not to blame for this. Neither is Windows or the motherboard. Case manufacturers constantly look to reduce costs, and the first elements to suffer the consequences are the USB ports, along with the rest of the front panel (power and reset buttons, headphone connectors, and more). Unless you decide to buy an ultra-high-end case with spare parts available through official channels, you must accept that front USB ports have a very limited number of cycles, and sooner or later they will abandon you.
My most recent personal experience was with the Cooler Master MasterBox Q300L. I love that case for several reasons and I have no plans to replace it, but one of its front USB ports started failing after just 40 or 50 cycles, and the second one didn't take long to follow. Unfortunately, Cooler Master does not offer spare parts locally, and given the cost of international shipping and taxes, it's better for me to buy another new case.
In short, if the front USB ports are not working, this guide should help you clear up several doubts before thinking about a direct replacement, whether by changing the I/O module, soldering new ports (yes, that is also an option), or buying a case. Much patience, and good luck!