InstallAware

I have found that using the built-in DIFx Driver Install plug-in (under WinXP) does not work for drivers which have not been WHQL certified. Calling DPInst.exe directly was working fine (as has been reported in the past in other posts), so I set out investigating the problem...

It appears that the DIFx plug-in always calls DPInst.exe with the "/S" command-line switch for silent installation. In my testing, I found that attempting to silently install non-WHQL drivers under XP will fail presumably because XP must be able to prompt the user that the drivers are not certified. (Note: I did not test under Vista because if it wasn't working on XP then I didn't care about Vista--and my understanding is that XP is a little pickier about WHQL than Vista or later versions of Windows.)

Ideally, there should be a way to have the DIFx plug-in omit the "/S" switch and, instead, use the "/SW" switch (suppress wizard) and, maybe optionally, the "/SE" switch (suppress EULA). This, IMO, is just as "silent" as using the "/S" switch (at least for my driver packages), but allows the OS to pop up mandatory prompts.

In the meantime, as initially implied, the workaround is to call DPInst.exe directly with the correct command-line switches. As a side note, it seems that drivers can be built under the newer Microsoft Driver Framework in such a way that XP will not require a pop-up message--I have no citation for this hearsay and, anyway, it may not be a desirable solution for existing drivers that otherwise work fine.

Thanks for making this contribution! I will pass this on to R&D so they can fix this behavior.

Please contact me privately with your email address so I can send you a custom build with these features direct from R&D.

I had a same issue with installing on XP. I found that I had to add legacymode to the dpinst.xml for it to show the driver licensing window...something like below

<?xml version="1.0"?>
<dpInst>
<suppressWizard/>
<quietInstallStrict/>
<forceIfDriverIsNotBetter/>
<legacyMode/>
</dpInst>

Without legacy mode with Non-WHQL drivers then it installs fine on all OS apart from XP where it throws up issue that cannot install unsigned drivers as seen in DPInst.log file in C:\windows\. I believe this flag setting is redundant for vista/win7 as you cannot add unsigned drivers without user approval. So without the legacymode flag on then win2K/xp dpinst would believe that drivers are signed and try and install and raise unsigned error. On vista/win7, the error would not occur as always requires user interaction....I think...well it worked anyway!

Dear MatthewFinch,

Thank you for your comments! Hopefully this will be helpful for future reference.