Hi. I have a bit of complicated problem here, so bear with me.
I have total of 10 USB Ports - 6 of them are USB 2.0, the other 4 are USB 3.0 ports. I have two 2.0 ports in front of my computer, two 3.0 ports on top of my computer, four 2.0 and two 3.0 behind my computer (as seen in the pictures, that I hopefully didn't forget to post.) Note: The two front 3.0 USB ports don't look like 3.0 ports, because I took the blue thingies away, but they didn't work even before I did that. Note 2: The USB 3.0 driver has an exclamation-point-sign in front of it (see picture), so that's another story. I want to focus on the 2.0 USBs first.
So, this is where it gets tricky. My mouse and my keyboard work, BUT only on the two middle USB ports on the back. If I plug them anywhere else, they won't work. BUT if I plug anything else in those two USB ports in the middle (on the back) it doesn't work! So only my mouse and keyboard work on those two, and everything else doesn't. And all the other ports don't work. Not even for my mouse and keyboard. But, if I plug in my external Hard Disk in any of the ports, except the front ones, the LED glows. (When I plug something in the front ones, it's really hard to do it, so I think those are a whole other problem, but I hope we can fix those too, because I need them the most, because I'm too lazy to turn my pc around every time I want to plug something in.)
Note: I have already re-installed Windows 7 to see if it would solve the problem, and it didn't, which suggests that it is a hardware problem, rather than a software one.
My computer specs: HP Pavilion HPE h8-1335ez Desktop PC Product Specifications | HP® Support
I think that's all the info and I hope you understood all of it. as I said, my problem is a "bit" complicated.