Gor,
After delving into several areas of the HP website (plus some other very reliable sources like computersurgeons.com,) I basically concluded that your controller is NOT Win7-compatible.
Basically, when a driver (ethernet for example) is in the form of a text document (.inf, .sys, etc.,) typically you can count 10 lines down from the top (after opening it) and changing the coding. (example: realtek = value of 8187 is now 8197 for vista compatibility. However, the specific driver you need only comes in a Windows Installer-based module. It's considered firmware; bottom-line, it's impossibe from a consumer standpoint to force "forwards-compatibility" before they're ready to provide it.
In one specific area of HP.com, they actually (laughably) said to use Windows/MicrosoftUpdate.
It's definately recommended that, since you went through the trouble to reformat, that you get a second opinion, but I will definitely put my money on the fact that this specific controller is designed for an XP platfom. (Also, FYI, Vista compatibility just became available recently...)
Your last option could be to contact tech support directly or find a way to get ahold of them withOUT paying their outrageous service fees. Here's one place to start:
HP Support & Drivers
Also, a secondary option would be to download HP's proprietary diagnostics utility for your hardware. Google (with quotes) "HP Hardware Diagnostic Tool"; It should, at worst, run as an ActiveX browser plugin. It'll detect issues off the bat. Unfortunately, you'll of course, have to save it to a flash drive or something from another PC.
I hope this helps.
Regards,
Erik
OceanicAirlines