USB-driver problem-out of idées

Problem with drivers for USB:
1. I connected a USB-soundcard (Line6) to my computer. The system detects
the unit with its name so the system can communicate with the unit.

2. When installing the driver the systeme respons: "An error occured during
installation of the hardware,
incorrect data" (free transation from swedish!).

3. I bought a new PCI/USB-card. The system detects the new PCI/USB-card but
also I can see that drivers for the new "USB" are missing.

4. When trying to install the driver the systeme respons: "An error occured
during installation of the hardware, incorrect data (free transation from
swedish!).

I have updated all programs, XP (SP2), USB, and chipset on mothercard.
I am an administrator.

I am now complete out of idées so I am looking forward for any comments or
idees.

Best regard