Nvidia drivers - failed install - 'system not modifed' ?

[MMclachlan]

Anyone have a fix/reason for the 'system not modified' error whilst trying to install Nvidia drivers after a failed install?
My system is Vista 64 with 2x 8800GT in Sli. P5N-T mobo, 4gb RAM and Q9550 @ 3.4. I had the 195.62 drivers installed, downloaded and tried to install 196.12 and the installwizard hung on the installing screen. I closed the installer, then re-ran it. It went through the motions, then 'finished' in a fraction of the time with the message 'system was not modified at this time, re-run installer at a later date to install'.
Since then I have;

*Uninstalled All nvidia drivers, inc chipset and PhysX, booted into safe mode and ran driversweeper 2.1.0. I removed the graphics devices from device manager then tried the install
*Used system restore to roll back to a few days ago then tried the install
Neither of these options worked with the same message coming up each time.
*I tried the 'update driver' option in the device manager - This said drivers found but access is denied. (although I'm pretty confident this method wouldn't work for enabling Sli even if the drivers had installed.)
*I tried deleting the Physx installer from the driver package and installing and also running taskman to see if I could kill the physx process, but this didn't work either.

Basically I have tried all the ideas I've found on forums out there and none have worked. This is the second time this has happened, and last time I did a fresh install, but as this install is only a few months old I am going to try and repair windows and see if this does it.

My question is why is this happening? There is clearly something that is 'started' during that failed initial install so the installer package will not then complete if run again afterwards, but nothing I've tried has been able to clear it.
What is your recommended process for future driver installs? I have never had problems (until Vista) with installing the new driver without removing the old - the package has always sorted it out on XP. I only used to do a uninstall and clean if I was swapping gfx vendor.

I'd really like to know what is causing this issue as a repair install or format every driver change is not really ideal. Especially with Sli as you pretty much have to run the newest driver out as Nvidia make you wait 2-3 months before adding support for your newest games.

 

[Guest]

If you have Microsoft Security Essentials on your system or some other Anti-Virus such as Avast, you might need to disable it first before installing the updated drivers, then once you finish updating you can re-enable your Anti-Virus program.

 

[SHIELDHEAD]

hey ill tell u flat out i wouldnt upgrade to the new drivers i did that yesterday and i nearly crashed my OS... idk why but i played a game for 15 mins and then it crashed in an extremely weird way. my advice is that its a bad driver set and stick w/ the 195.?? drivers like me!

 

[MMclachlan]

I ended up having to do a fresh install as nothing worked at all. I couldn't roll back the drivers to the previous version, the vista upgrade install (xp repair equiv) did nothing either.
I put the 196.12 drivers on when I re-installed and then went in OK. I think in future the safest way to update these video drivers is to do an uninstall first, and preferably have a backup of your system drive to hand also!
On a side note the main reason I wanted to update these drivers was to add SLi support for Dirt2. It now seems that Dirt2 is utilizing my second card to about 5-10%! What a waste of 2 evenings of time!