Fingerprint reader refuses to install. Help!

I got my dv8t about a week ago, and the fingerprint reader that was pre-installed kinda worked, though it would drop out from time to time. I tried downloading an updated driver, but it flat-out refused to install. I didn't think much of it, but when I tried to do Windows Anytime Upgrade, it destroyed everything on the hard drive, including access to the recovery partition. It's just gone.
Now, I've rebuilt the system from a Win7 OEM DVD, and everything works perfectly... except the fingerprint reader. The program that is causing the problem is Validity Sensors DDK. It gets to "Please wait while Windows configures Validity Sensors DDK." After about 10 seconds of that, the box disappears. The hard drive stops, and there is no longer any trace of the setup program in the Task Manager. I have the latyest version of Digital Persona, and it says no fingerprint reader is installed. However, Validity Sensor shows up in the device manager (VFS301, 2.1.0.2) and Validity Sensors DDK shows up in Add/Remove programs. I can uninstall it (really, i think it just removes it from the list) but the "repair" option does nothing. I have tried different versions of it that I've found in various places.

SP42724
SP43934
SP44089
SP45020
SP45021
SP45995
SP47224

Of the above SP's, I have tried installing them in regular mode, Admin, Compatibility mode, XP mode, and Safe Mode. None of them will get any farther than I have described above. One time, and only one time, I got the following error message:

An error occurred during the installation of assembly
'policy.8.0.Microsoft.VC80.CRT.type="win32-policy",version="8.0.50727.762",publicKeyToken="1fc8b3b9a1e18e3b",processorArchitecture="amd64"'.
Please refer to Help and Support for more information.

I have even tried extracting the files from what's left of the recovery disk, but I couldn't find the pertinent files anywhere. I can't boot from the recovery partition, so that's not an option. I feel like I've tried everything, but the installation program just refuses to work! I don't want to send back a $1500 computer for something so stupid. What have I forgotten? Why won't it install? Can someone just send me the installed directory so I can try to get that to work? Why can't HP release a fingerprint driver that works? HELP!!

 

Update: I tried it again with the install log feature turned on. I won't put the whole 578k file here unless someone asks for it, but here is the end of it:

MSI (c) (14:94) [14:45:37:071]: Product: Validity Sensors DDK -- Installation completed successfully.

MSI (c) (14:94) [14:45:37:071]: Windows Installer installed the product. Product Name: Validity Sensors DDK. Product Version: 3.1.374. Product Language: 1033. Manufacturer: Validity Sensors, Inc.. Installation success or error status: 0.

If it did, why won't DigitalPersona see it? And if that was a successful install, where are all the files? The download was 43MB!

 

Hi I'm having problems installing this driver as well. Except I'm doing so from a Vostro 3700. I'm a bit confused as to what you did to get the installation working.