Which is better, a usb wifi adapter or pci wifi card, for a desktop.
either is fine. I think you will find a pci has slightly more power,eg slightly more range, but also have removable antenna. Most notebooks have wifi built in anyway, so portability of the wifi unit isnt an issue. I'd be going with a pci wifi card myself, mainly because of the antenna options.
XP seems to have issues (on some Motherboards) with USB devices, so it
I had a choice, I would go with a PCI ethernet adapter.