I have an old Dell 4400 that has PCI 1.0 slots. I have not found a USB 2.0 card to use on this machine. I've tried the PCI 2.1 cards, but they lock up my system when I connect a device. Does anyone know where I can find a PCI 1.0 USB 2.0 card?

A card built to PCI 2.2 specs should be backward compatible to your slots. Do you have the motherboard chipset drivers installed? Original WinXP does not support USB 2.0. You should be running SP3. If you are using the slot closest to the graphics that slot may be sharing an IRQ with the graphics. Before connecting a USB device check the status of the USB card in Device Manager. See if it is working correctly and not sharing a IRQ with a high bandwidth device. Try moving the card to different slots. Older motherboards also had options to assign resources to certain PCI slots. In the BIOS look for an option for PnP aware OS. Try both Enabled and Disabled to see which gives better results. If you have IRQ conflicts there may be a BIOS option to reset data configuration settings. Try enabling for one boot cycle. Look at the link below. Pay attention to page 4. http://www.ece.mtu.edu/faculty/btda...

Where did you get the idea you have PCI 1.0 slots? PCI 1.0 was introduced in 1992, 2.0 in 1993 and 2.1 in 1995. The only Dell 4400 I could find is an early P-4--old but not that old. You DON'T have PCI 1.0 slots. As already mentioned, try the card in a different slot.

History of PCI: ( http://h20000.www2.hp.com/bc/docs/s... ) PCI 1.0 1992 PCI 2.0 1993 PCI 2.1 1995 PCI 2.2 1998 PCI 2.3 2002 PCI-X 1.0 1999 PCI-X 2.0 2002 Since that document was posted, in addition there is: PCI 3.0 2002 as well as PCI-express versions.