Gregavi

I have a Compaq PC with a P III;448 MHz;512 RAM running XP Pro that I am using as a digital music server. I have my music and photo files on two 500 GB external hard drives w/USB connection hanging off the PC. The internal 160 GB drive is for OS and a few programs only. I don't use this computer for anything other than pulling music and photo viewing with a Roku Photobridge (similar to squeezebox). I'm looking to possibly upgrade this PC with whatever would make it a little faster and more efficient. One reason for my desire to upgrade is when I connect my USB hard drives, a pop-up window states that I have connected a hi-speed (USB 2) device into a port that does not support hi speed devices (or something to that effect). The USB card that I am using is, I'm pretty sure, USB 2 capable, so I'm thinking the motherboard or something else is not hi speed device capable. Would a BIOS upgrade make a difference? Pulling music off of this PC seems a little slower than when I was using my newer, faster PC. Any advice is greatly appreciated.