Had this happen on my new iMac. Called Apple Support and was told I would have to remove the entire Bootcamp partition (erasing the Windows install in the process), verify that all Mac software updates were applied, then recreate the bootcamp partition and reinstall windows from scratch because "Windows 7 wasn't supported when you created the bootcamp partition so we can't update drivers"
Now, I realize we're talking about Windows here with an Apple tech but there was no way I could buy that explanation (this is my first Mac, but I happen to know a thing or two about PC's)
Now, a disclaimer:
A. I made a complete Windows backup (image and files) before starting this.
B. I haven't tested every piece of supported Apple hardware to make sure all the drivers updated, however, all of them
DID appear to get replaced and the Boot Camp icon About screen now shows version 3.1
C. I have the ATI4850 graphics in my iMac. There was an nVidia update included in the bootcamp 3.1 update which I did NOT attempt to install as Apple had a link directly to ATI to get the latest ATI driver in one of the iMac KB articles I came across while attempting to debug this.
D. If you aren't comfortable working in Windows, then you probably want to follow Apple Support's recommendations and just trash your partition.
E. I'm working with Windows 7 Ultimate x64 ... I haven't tried this with the 32 bit Bootcamp install file, so your mileage may vary
Step 1: Do all your updates on the Mac side. I don't know if upgrading the PC side to BC3.1 without doing the Mac side would cause any issues (it really shouldn't) but better safe then sorry
Step 2: Make sure you have backups of both your Mac and Windows systems just in case something goes horribly wrong and you blow your OS's to bits. This includes making the recovery CD in Windows 7
Step 3: Download the Bootcamp 3.1 update directly from Apple. The one that auto-downloads from the Apple Software Update isn't going to help you. I got mine from
http://support.apple.com/kb/DL979
Step 4: Get your hands on 7-zip. It's free and WINZIP wouldn't work for me (even with the latest version)
Step 5: This is a long one...
Use 7-Zip to open the BC3.1 .EXE file. The easiest way to do this is to right click the BootCamp
3.164-bit.exe file and select 7-ZIP, then pick the option that says "Extract to BootCamp_3.1-64-bit\"
This will create a folder called BootCamp
3.164-bit at the same spot where your downloaded install file was.
Open up this folder, there's a bunch of crap in here. There is a file called "[0]" that's the only thing of any size (281mb). Right click on that and select 7-Zip then Open Archive from the popup menu. This will show 3 files.
BCUpdateInstaller.exe
NvidiaGraphics64.cab
BootCampUpdate64.msp
I extracted all these to my desktop. The MSP file is a Microsoft MSI installer PATCH file.
Step 6: Right click on BootCampUpdate64.msp (if your system doesn't show file extensions this file has a standard Windows installer Icon -- the little PC with a software box and CD in front of it). From the menu that appears select the option "Apply". You should get a Boot Camp install screen asking if you want to either REPAIR or REMOVE Boot Camp. Select Repair.
When this finishes you will be prompted to reboot. Let the system reboot.
When everything restarts you should now be running BootCamp 3.1 without having to do a complete reformat of your Windows system.
I would recommend you visit the Apple support page and find the link to the latest ATI video driver (9.12 I believe) or visit the ATI download page directly as that's where the Apple support page sends you anyway. Download the latest Catalyst package for RADEON 4800 and you will be good to go.
If you are an nVidia user, you can use 7-Zip to drill into the NvidiaGraphics64.cab file that you extracted earlier... eventually you will get a while folder full of files with a regular SETUP.EXE from nVidia. That should do the trick but I can't test that....
Good luck
