Did you at any point try to install something that didn't install?
Have you checked device manager?
<Windows Key> and <R>, then type
[blue]devmgmt.msc[/blue] and press <Enter>. Look for anything with a question mark or exclamation mark. If you see something that is such, and you know you aren't using anyway, just right-click and disable it. If it's something you think you need try to right-click and Update Driver.
If you don't know what it is, then you can find the hardware code this way:
Well, here's a freeware program built for the purpose, but it may be just as simple to do it on your own:
Pretty nifty... here's a site reviewing various apps for the purpose:
Oh yeah, almost forgot about this one. If the driver doesn't have a digital signature, then Windows may be blocking it being installed. Check here about 2/3 down the page to see more on that:
Well, here's the instructions, I just went through it myself to remember:
[OL][LI]In Device Manager (see above), right-click on the item that isn't installed correctly or at all.[/LI]
[LI]Select
Properties from the pop-up menu[/LI]
[LI]Click the
Details tab.[/LI]
[LI]Make sure
Device Instance Id is selected in the drop-down.[/LI]
[LI]Left-Click to select the number/code starting with [BLUE]PCI\EV[/BLUE][/LI]
[LI]Use the keyboard shortcut,
<ctrl> + <b> to copy the text.[/LI]
[LI]Go to www.google.com[/LI]
[LI]Paste the value in the search box, and add the words,
[blue]driver windows xp[/blue][/LI]
[LI]Or if you can't find it yourself that way, try posting it here, and one of us may can help.[/LI][/OL]