|Some cheap desktop cases have inadequate wiring for the front USB ports. The only way of fixing that is to replace the wiring.|
How do I know ? I have one of those, and a friend does too.
(You can have the same problem if you use an old case with front USB ports that was made before USB 2.0 controllers and devices were available with a newer mboard that does support USB 2.0 devices. )
For the front ports (lower down) in my case, corded mice and keyboards are recognized fine, but flash drives nag you about they would work better if the port supported USB 2.0 or similar despite the fact the mboard does, external hard drives are not recognized.
On my friend's case, the (lower down) front ports won't allow the recognition of his printers or his external hard drive.
(He paid about $55 for the case, which came with an el-cheapo 500 ? watt PS - I didn't like that PS and convinced him to get a better one and not use that PS at all.)
If you can handle a simple soldering job, or if you know someone who can, buy yourself a USB wiring adapter meant for installing in a slot space at the back of the case that has two USB ports in a bracket you install in a slot space, that is rated for USB 2.0 use, remove the wiring from that at the bracket end, remove the wiring from your (lower down) front ports at the ports end, solder the better wiring to your front parts and they'll work fine with all USB devices.
OR - cases often have USB modules for the (lower down) front ports - there are only so many types / sizes / ways of mounting them - however finding one that fits / mounts in your case properly that suppports USB 2.0 specs is unlikely, and they usually don't come with the wiring.
If you have front ports higher up on the front of the case, they may be two ports in a USB hub that connects to one USB port connection on the mboard - it's wel known USB ports in that type of hub do not allow all USB devices to be recognized properly. They're sharing the 500ma max available from the one mboard header connection. E.g. one external hard drive may work in a port, ONLY if nothing is in the other port there.
(External hard drives and external optical drives require 500ma is available from the USB port.)
The USB ports lower down on the front are usually each connectecd to one USB port connection on a mboard header.