I was diffing around and found this:
I had to restart right after (prompted me this) and had to change to 32bit colour manually.I have successfully loaded the ATI Mobility Radeon 7500 Driver from the SP27665 (an HP/Compaq driver file). I have a Compaq EVO N800c. The install does not work, however it will extract the files to: C:\swsetup\SP27665\Driver\2KXP_INF. Then under Device Manager choose to Update Driver (under the Generic VGA) , select Brows My Computer; choose Let Me Pick, say Have Disk and browse to the above folder ( C:\swsetup\SP27665\Driver\2KXP_INF). 2 options appeared for me, I chose the first, my system start dinging and flashing a few times (around 10) and then all was normal. I did not say to reboot, but I tested Freecell and it said there was no hardware acceleration still, so then I did a reboot and presto! no more message about Hardware acceleration being disabled and the cards fanned out in there fancy way. I've only done this about 5 minutes ago, so I don't know how things will function long term, although I've also only been running 7 for about an hour... Hope this helps.
Link to the thread: http://www.sevenforums.com/graphic-card ... 0-a-2.html
And direct download link: ftp://ftp.hp.com/pub/softpaq/sp27501-28000/sp27665.exe
I installed Windows 7 Ultimate to my Radeon 7500 equipped T42 and these drivers worked OK, even played 720p HD videos very fine in Youtube. Aero obviously don't work, but Direct3D works OK. Didn't try OpenGL. On 3DMark2001SE it gave around 4000 points which is in the ballpark compared to XP (few hundred points down). GTA Vice City worked also flawlessly for an hour or so.
No BSOD's or anything unusual, resume from sleep etc work.
Hope you make use of it!