USB plugs not working-very old desktop tower...inspiration from late 2004 or early 2005

none of my usb ports are working.  the ones in front got so I could not plug anything in; now all the back ones I can plug in, but it sys on the monitor the system has recovered from a serious error...and welcome to the found new hardware wizzard to instal usb composit device.  since both my mouse and keyboard are usb powered, I can't click on anything.  Also, the connection to the internet (ethernet plugs) are not working either so I cant even get someone to troubleshoot.  I have important things in the tower stored....help! please?  I looked up to see if the mic plug can be converted to usb but I think only for power. I have and OS of xp sp3 and am really not sure what number inspiration it is