Following up on the “Unknown devices on IBM servers” post, let me talk about a similar situation with HP machines (DL180 G6, in my case).

The device that Windows fails to identify is this one:

More info can be found by looking up the IDs in the pci.ids file (as I often do), or by means of the various “Unkown Device Identifier” type of software (e.g. this one). If you have a Linux machine at hand, such a one-liner may suit you:

What’s missing is an Intel SATA driver; needless to say that you won’t find it anywere on HP site.
I downloaded and installed the Rapid Storage Technology Driver from Intel’s web site (here). A 280KB download named “STOR_all32_f6flpy_9.6.0.1014_PV.zip” fixed things up for me.
Maybe the proper thing to try would’ve been the latest (March 2010) Proliant Support Pack, but it’s a big download and I didn’t have the time. Also, the onboard SATA controller isn’t really used (the additional SAS RAID is, instead) and I just wanted to get rid of the yellow warning sign in Device Manager.