Many users are having problems finding drivers that Intel releases that doesn't release to the "Graphics" page or the automatic finder utility, Here's how you find the hidden ones.
For example, my desktop board is DH67BL. First I find the location for the motherboard download page. Support-Desktop boards-DH67BL-Drivers & Software
When you get there, you can see few driver versions released between April and the September driver.
That's the only thing its listed. The 2509 September driver doesn't exist on the motherboard page. But even more has released than those two:
2376, 2418, and 2410
The hidden drivers just appear on product pages from time to time. The timeframe between releases are little as 15 days to long as 1.5 months, but certainly not long as 4-5 months as some are suggesting.