According to DPInst.doc, You should only run DPInst in quiet-install
mode in situations where no user interaction is potentially required to
complete an installation. One of typical situations that require user
interaction is: (1) Windows prompts a user before installing an
unsigned driver package.

With above, I can't use quietInstall because of I am installing an
unsigned driver package even with legacyMode on! Then, I tried with
suppressWizard with legacyMode ON, it works but still prompt a warning
for "not passed Windows Log testing". How can I suppress this warning
as well?