Question : Problem: USB Devices not recognized

About 4 days ago I built this computer from spare parts that were laying around the office. It is an HP MS-7184 motherboard with a AMD x2 4200 processor.
     It was working fine for about 3 days. I installed a PCI sound card and it was working fine. The next day I booted the machine the mouse started to lag and eventually shut off. I rebooted but it kept doing it. I decided to remove the sound card since it was the last hardware changed. I was still having issues.
        I removed the usb mouse and used a regular ps2 mouse. Now whenever I plug any usb device including thumb drives into the usb ports it says "usb device not recognized." Sometimes it will detect the mouse, but it only works for about 10 seconds, then the red laser shuts off and the mouse stops working. I have also gone into device manager and uninstalled the usb devices, rebooted machine and redetected the usb ports, but I still get the error message or mouse doesn't work.
         I reformatted the hard drive thinking it had something to do with a software related issues, but it still keeps happening. All my drivers have been installed and the latest updates from microsoft were also installed. I have tried unplugging all other devices like CD-ROM, other hard drive, PCI cards, but it still keeps happening. I would greatly appreciate any ideas because I am desperate right now. Thanks.

Answer : Problem: USB Devices not recognized

First, check the bad capacitor on motherboard:
http://www.badcaps.net/pages.php?vid=5
Second, to clean and reapply thermal paste between cpu top surface and heatsink.