Testing underway. Will report back shortly.
EDIT: Either I screwed it up, or there is more to it because it didn't work. I'll collect up my setup logs and NV4_GO.INF file and post them shortly.
EDIT: NV4_GO.INF and setup log here: http://www.mediafire.com/download.php?ktmlglmyljr
Also, this looks like the problem in the setup log:
[2009/12/14 15:07:51 844.1298 Driver Install]
#-019 Searching for hardware ID(s): pci\ven_10de&dev_029a&subsys_019b1028&rev_a1,pci\ven_10de&dev_029a&subsys_019b1028,pci\ven_10de&dev_029a&cc_030000,pci\ven_10de&dev_029a&cc_0300
#-018 Searching for compatible ID(s): pci\ven_10de&dev_029a&rev_a1,pci\ven_10de&dev_029a,pci\ven_10de&cc_030000,pci\ven_10de&cc_0300,pci\ven_10de,pci\cc_030000,pci\cc_0300
#-198 Command line processed: "C:\WINDOWS\system32\setup.exe" -newsetup
#I393 Modified INF cache "C:\WINDOWS\Inf\INFCACHE.1".
#I022 Found "PCI\VEN_10DE&DEV_029A" in C:\D\G\N1\nv4_go.inf; Device: "NVIDIA Quadro FX 2500M"; Driver: "NVIDIA Quadro FX 2500M"; Provider: "NVIDIA"; Mfg: "NVIDIA"; Section name: "nv_WSApps_NV3x_Mobile".
#I087 Driver node not trusted, rank changed from 0x00002001 to 0x0000e001.
#I023 Actual install section: [nv_WSApps_NV3x_Mobile]. Rank: 0x0000e001. Effective driver date: 11/20/2009.
#-166 Device install function: DIF_SELECTBESTCOMPATDRV.
#I063 Selected driver installs from section [nv_WSApps_NV3x_Mobile] in "c:\d\g\n1\nv4_go.inf".
#I320 Class GUID of device remains: {4D36E968-E325-11CE-BFC1-08002BE10318}.
#I060 Set selected driver.
#I058 Selected best compatible driver.
#-124 Doing copy-only install of "PCI\VEN_10DE&DEV_029A&SUBSYS_019B1028&REV_A1\4&1C9EC085&0&0008".
#E360 An unsigned or incorrectly signed file "c:\d\g\n1\nv4_go.inf" for driver "NVIDIA Quadro FX 2500M" will be installed (Policy=Ignore). Error 0x800b0100: No signature was present in the subject.
#-166 Device install function: DIF_REGISTER_COINSTALLERS.
#I056 Coinstallers registered.
#-166 Device install function: DIF_INSTALLINTERFACES.
#-011 Installing section [nv_WSApps_NV3x_Mobile.Interfaces] from "c:\d\g\n1\nv4_go.inf".
#I054 Interfaces installed.
#-166 Device install function: DIF_INSTALLDEVICE.
#-035 Processing service Add/Delete section [nv_WSApps_NV3x_Mobile.Services].
#E032 Error 0xe0000217: A service installation section in this INF is invalid.
#E275 Error while installing services. Error 0xe0000217: A service installation section in this INF is invalid.
#E154 Class installer failed. Error 0xe0000217: A service installation section in this INF is invalid.
#I060 Set selected driver.
#-166 Device install function: DIF_INSTALLDEVICE.
#E154 Class installer failed. Error 0xe0000203: There is no driver selected for the device information set or element.
#-166 Device install function: DIF_INSTALLDEVICE.
#E154 Class installer failed. Error 0xe0000203: There is no driver selected for the device information set or element.