I installed an Iogear 5 port USB 2.0 card with no problems. Device Manager shows normal entries with no warnings or errors. If I boot XP Home with any device plugged into the card XP always freezes at the Welcome Screen. With no devices powered the boot is normal. If I power a device (I have an external hard drive and a scanner) after boot it will sometimes function normally and sometimes cause XP to freeze. Sometimes it with the external hard drive it will work and then freeze in conjunction with a mouse click in Windows Explorer (not necessarily the first click and not necessarily on a folder in that hard drive). Both devices work normally 100% of the time with USB 1.1 ports on the same machine. I've tried two separate PCI slots with the same results. Is this a bad card or is there a conflict with XP somewhere? My OS has all current updates installed.

service pack1? it fixes the 2.o problems

Did you install the drivers that came with the PCI card? If you did, that might be the problem. Uninstall those drivers and do as hallo says. Install SP1. Microsoft has included support for USB 2.0. Did this work?

Thanks for your responses. All problems I described occur with SP1 installed and no drivers specific to the PCI card installed. Any more ideas?

Dumb question here - are the devices and cables specific to USB 2.0?

Yes, both my external hard drive and scanner are USB 2.0 devices. As I said, if I wait to power them up until after XP is up, they do intermittently work at USB 2.0 speeds through the PCI card. But a majority of the time their use through the card freezes XP.

Well, we've all gotten a hold of bad PCI cards. That would be my guess. If it was me, I would return the card, get my money back and buy one made by a different company.