Have just put together new system using Gigabyte GA-M55plus-S3G all in one board (rev 2.1) with XP Pro SP2, AMD 4600 X2, 320GB Seagate SATA drive, 2 x 512MB A-DATA RAM. All was going well but system started to not play ball with ANY USB devices that I now plug in. I mostly get the message now that 'One of USB devices attached to this computer has malfunctioned and Windows does not recognise it'. This includes basic mice, k/bds, etc. I completed a fresh install last night again (my XP has XP2 with it) and then installed all M/b drivers, have even updated BIOS with the latest version). Have enabled USB k/b and mouse support in the BIOS. The USB drivers shown in the USB Root Hubs seem to be the standard Windows variety (5.1.2600.2180) which are the ones that are also with the m/b driver disc. Have also tried unistalling all drivers related to the USB controllers and then restarting Windows (which loads all drivers in again after recognising new hardware). I am typing this with a ser.k/b and a mouse with a ball! Had to look through my junk box to find the mouse. I would greatly appreciate any advice as I have spent hours on this and have reviewed hundreds of posts searching.