When do you really need to use DDU?

[beury]

DDU is often used as the solution to try when sorting out possible driver issues. At the same time, I've seen it suggested that it should be used whenever you make a hardware change, regardless of which path you go to. A common reason I heard is that the OS can get confused as to which driver to use. Although I haven't seen it, I have a feeling that people also think that because when you get a driver package from AMD or NVIDIA, they make you choose a specific model of graphics cards, and thus what you get only works with what you selected.

So I wanted to tackle a scenario since I was able to do this recently: Do you need to use DDU when upgrading from one NVIDIA card to another? The tl;dr is no, you don't.

Spoiler: Background: how does Windows handle drivers?


Spoiler: Test Setup


Spoiler: Results


Spoiler: So when should DDU be used?

However, if you want to continue suggesting that someone DDU the drivers anyway, I'm not going to stop you. This is just a post sharing what I've researched, what I've tested, and what I've concluded.

[Parisien_entraide]

In our forum (in French) DDU often solves a lot of problems related to the change of graphics card, even if you change an Nvidia by an Nvidia for example

If all goes well we don't touch anything
If there is a problem, DDU is the best solution

Then we do not take an isolated case to draw generalities (sophism)
So I just take user issues

But if I take a particular case

For example I have computers under Windows 7, Windows 10, Windows 11, Linux (several distributions))

Here I just changed an MSI Nvidia 970 Gaming, for an MSI Nvidia 1660 super Gaming for the test computer under Windows 7 (with an I7 2700K)

In the games everything seems to work apparently... But in fact the card was not even recognized with the test or analysis programs (GPU Z etc) and therefore was not exploited

In the device manager there was a yellow triangle for the card, as well as the USB and PCI controller

There was a bios reset, a new installation of the drivers (and others) , but nothing changed
Worse.. some games indicated that DirectX 11 was not installed

The solution came with DDU for the graphics card and above all by erasing the settings

There is only the USB/PCI driver which is not installed (normal it is USB-C which does not exist for Windows 7) Just deactivate it
(USB Type-C Port Policy Controller)