What Is DRIVER VERIFIER? How To Use It To Troubleshoot Driver Issues

Driver Verifier is a Windows software used to observe and stress drivers to detect any unintended conduct. It’s a software meant for use on improvement techniques by driver builders reasonably than on manufacturing techniques by regular customers. Actually, Microsoft cautions customers to do the identical.

Nonetheless, you’ll usually see customers on boards being suggested to make use of Driver Verifier to troubleshoot driver points and BSODs. So, what’s the truth? Is Driver Verifier protected to make use of, and must you apply it to your system? We’ve tried to reply these and related queries on this article.

What Is Driver Verifier? Ought to You Use It?

Windows NT Machine Drivers use kernel mode constructions known as I/O request packets (IRPs) to speak with the OS and one another. The Driver Verifier screens these IRPs and checks for IRP task and completion errors.

The Driver Verifier permits you to put drivers by heavy stress masses by simulating sure circumstances like low reminiscence, pool monitoring, or impasse detection. You possibly can recreate potential errors by forcing drivers to work with minimal sources and use the generated dumps to investigate and debug the issue.

As said, that is typically carried out in take a look at environments when growing the drivers. However generally, you’ll need to run the Driver Verifier on manufacturing machines. And there arises the query, is that even protected?

Effectively, it’s sophisticated. Initially, Microsoft has explicitly cautioned in opposition to attempting to confirm all drivers without delay as this might severely degrade efficiency, restrict the effectiveness of the verifier, and just about make the system unusable. And but, that is how most customers use the Driver Verifier.

However it’s additionally true that in uncommon instances, even should you use the Driver Verifier correctly, you would nonetheless get caught in a Driver Verifier bugcheck loop. Basically, it may trigger more crashes than it solves. However like we stated, that is extremely unlikely to occur if correct process is adopted

Finally, our verdict is that it’s best to solely use this on manufacturing machines should you’ve already tried different debugging instruments with no success.

How to Use Driver Verifier?

Driver Verifier is included by default on most Windows variations and may be run with the verifier command. However earlier than you run it, there are some things value noting first:

Generate Bug Test

For maximal effectiveness, Microsoft recommends organising network debugging. However this isn’t possible for many customers, and no matter whether or not you arrange the debugging session or not, the steps to observe on the goal (crashing) laptop are the identical:

1. Press Win + R, sort verifier, and press Enter.
2. You have got two choices with the Driver Verifier Supervisor.
   
   • In case you suspect there’s a particular cause on your driver points, like, let’s say, reminiscence corruption, you would choose Create Customized Settings (for code builders), and you would choose explicit exams like Particular Pool.
   • In any other case, you would choose Create customary settings for the default exams.
   • When deciding on customized settings, there are some things value noting. As Randomized low sources simulation has a chance of inflicting unrelated crashes, this take a look at is not included typically. You possibly can as an alternative go along with Systematic low sources simulation.
   • Some generally included exams embrace Pool Monitoring for reminiscence leaks, I/O Verification to test for unlawful I/O routines, Impasse Detection to test for impasse potential, Safety Checks to test for safety vulnerabilities, and so forth. We suggest referring to Microsoft’s Driver Verifier Choices documentation for the complete record and outline of the choices.
     
3. After specifying the take a look at, decide Choose driver names from an inventory.
4. Choose the driving force/s that you simply suspect and press End.
   
5. Restart your laptop and use your system as traditional.
6. The system efficiency will probably be affected throughout this time, nevertheless it’s supposed. After Driver Verifier detects a violation, it can generate a bug test.
   
7. Now, it’s best to restart and analyze the dump information to find out the foundation of the issues and reset the Driver Verifier afterward.

Observe: If you wish to be environment friendly, you can even run Driver Verifier through the command line if you would like. As an illustration, the next command runs it with default settings on a driver known as TestDriver.sys:
verifier /customary /driver TestDriver.sys

Analyze Minidump File

You need to use debugging instruments like WinDbg or KD to investigate the dump information and determine the defective drivers. In both case, for the CLI strategies, you’ll first wish to append the image path to level to the Microsoft image retailer. 

This may enable the debugger to robotically retrieve the proper image information with out requiring data like product names, releases, or construct numbers from you. You are able to do this with the .symfix command as such:
.symfix[+] [LocalSymbolCache]

We’ve carried out the identical and confirmed that it labored by utilizing the .sympath command within the proven instance. Do notice that web entry is required for this to work.

KD

With KD, you should use the kd -y SymbolPath -i ImagePath -z DumpFileName command in CMD to open the dump file. On the KD immediate, you should use !analyze -v to investigate the dump file and !verifier to show the Driver Verifier stats.

WinDbg

Within the case of WinDbg, you are able to do the identical with windbg -y SymbolPath -i ImagePath -z DumpFileName. Alternatively, you can even use the WinDbg Preview app through the GUI as such:

1. Set up and launch the WinDbg software.
2. Press CTRL + D, then browse and open the .dmp file.
   
3. Choose View > Command and enter !analyze -v.
   
4. After the evaluation is completed, test the MODULE_NAME and In all probability brought on by sections.
5. As you probably have a number of dump information, analyze the remainder in the identical method to find out the offender.

Reset Driver Verifier

Driver Verifier consumes a big quantity of sources when stress-testing the drivers within the background. In case you don’t reset it after utilizing it, your system efficiency will keep degraded, and also you’ll proceed to face crashes because of the bug checks. 

As such, you’ll wish to reset it by launching the Driver Verifier Supervisor as earlier than and deciding on Delete current settings. Alternatively, you would additionally use the verifier /reset command in CMD.

In case you’re unable to disable it attributable to direct crash upon booting, you possibly can boot into protected mode and disable it from there. Assuming you adopted our suggestions, Driver Verifier ought to solely be operating in opposition to non-Microsoft drivers, which received’t be operating in protected mode, that means it’s best to be capable of boot with out crashing.

In case this isn’t an possibility both, you possibly can boot from a Windows Set up Media or Recovery Drive and use system restore to revert your PC to a working state.

Resolve Driver Points

When you’ve singled out the problematic driver, you possibly can take the suitable steps, whether or not that be updating it, rolling again, or uninstalling fully.