Hi:
I would run the Windows 7 Upgrade Advisor and see what it reports.
http://www.microsoft.com/en-us/download/details.aspx?id=20
I can tell you that the onboard Intel Graphics adapter cannot run Windows Aero, and the only workaround I know of is to install Windows 7 32 bit, and manually install the Intel graphics driver for windows vista from the HP nc6220 notebook PC.
That driver will allow you to change the screen resolution and enable graphics acceleration but no Aero.
There is no Intel 64 bit Vista or W7 graphics driver for the Intel GPU.