I looked up your HPw2338h & it has HDMI support, too bad your GeForce GTX 260 does not have an HDMI connector. You shouldn't have gotten a DVI-to-VGA adapter. What you should have gotten, IMHO, was a DVI cable ... you have a monitor with DVI support & a video card with DVI support. I could understand getting a DVI-to-HDMI if you were trying to connect to the display via HDMI.
HP has some suggestions for users with that monitor, you should check it out & do let us know if you need more help.
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