Win7 x64 seems to be missing core USB->serial drivers  

Hi all,
I recently had to reformat my machine and reinstall Win7 x64.
It's been a while now, and everything is back up and running just fine for the most part.
However, the other night, I decided to reinstall my 3D printer, which is a Monoprice Select Mini.
This printer seems to use a simple inf file to point to the built-in Windows USB->Serial drivers.
For reference, I'm able to install this printer on my laptop (also running Win7 x64) with no issues.
When I plug the machine into my PC and power it on, I get the standard 'USB connected' sound, and the hardware wizard notifies me that it's attempting to find the driver. It fails to find anything on Win Update, which is expected. Once it's done, I go into device manager and right click on the new hardware entry, and choose to update the driver. I point to the provided inf file, and it proceeds with the install. I get a message about an unsigned driver, which I accept. I should mention that the driver failed to install at all with a "file not found" (or similar) error until I hunted down the fact that it was looking for usbser.sys and manually copied it to my system32/drivers folder from my laptop. Not sure why it wasn't there before. I suspect this has something to do with the root cause of my troubles here.
Anyway...at this point, the driver fails to load, because of the unsigned issue. If I reboot and disable driver signing enforcement, then reinstall the driver, it will complete the installation, but then I get a (code 39) error telling me the driver is corrupted.
I finally found a reference to the setupapi.dev.log file and found in there where the driver install is failing, but I can't read it clearly enough to understand what exactly is the failure point.
I'm at a loss here. I've done countless uninstalls and reinstalls of the driver. I've even tried system restores back to a point before I installed any version of the 3D printer driver, thinking maybe I did something in the wrong order, but it made no difference. I've also run the SFC, and apparently no errors were detected, since the tool closed with no messages.

Any advice greatly appreciated!
-Mike

if you just installed win7, did you also go through the 4-5 hour process of getting all your windows updates current? If you did, and you also ran every motherboard driver package that exists for your motherboard, and then ran the installation software for the printer, you should be good to go.

Installation | Ultimaker: 3D Printers

p.s. it would help to know your exact hardware specs

Yes all updates are current, for Windows and desktop hardware.
This isn't exactly a "new" Windows install. I did it a couple months ago, but I'm just now getting around to reinstalling the 3D printer.

There isn't any "installation software" for the printer. As I mentioned, it only uses a simple inf file to point to some supposedly built-in Windows drivers that appear to be MIA on my system.

Hardware specs of what, the printer or my PC?

I did on a search for your printer driver and the manufacturer's site said to install the software that I linked above. If you have done that, and your device manager is clean, and you have installed all the driver packages from your motherboard's site, some of which will override the windows default drivers that get installed by windows at installation, then I am not sure what else to recommend.

Thanks for the suggestions, but that software isn't for my printer.
My printer is a Monoprice Select Mini. It has nothing to do with Ultimaker.

You make a good point about checking motherboard drivers, though. I'm not certain I've specifically done that, since after install, I check device manager and there were no outstanding issues, so I went to work.
It's possible that I still need to update some drivers, even though they aren't showing issues.
Which packages specifically should I be looking for? I assume chipset, but what else?
I know there's a USB3 driver for my board, and I had to install that, since this is one of the early boards that supported USB3 with an add-on chip.

Elmojo said:

Thanks for the suggestions, but that software isn't for my printer.
My printer is a Monoprice Select Mini. It has nothing to do with Ultimaker.

Its best to install every motherboard driver package that is listed on your board's site for your board. You never know when one component is dependent on another component.

I found that link after reading the below, which is from monoprice.com q&A, found in this link...
MP Select Mini 3D Printer - Monoprice.com

"About: MP Select Mini 3D Printer When I try to connect it into my pc, it says it doesn't have a drive, where can I install it?
A shopper on Dec 25, 2016

BEST ANSWER: Hello, thank you for your question. The necessary drivers are included in the CURA software on the SD card provided. You can also download CURA (Version 15.04.6) directly from the Ultimaker website. I hope this helps, and of course if you have any more questions feel free to contact us!

- Jeff M Staff on Jan 18, 2017

That's actually bad information, but I see where you got it now. This is a perfect example of why you shouldn't believe everything you read on the internet. lol
Cura is a slicer. A slicer is a program that 'slices' up a 3D model into the layers that the 3D printer needs to be able to "print". It has nothing to do with actually sending the data to the device. In fact, the "correct" way to send a job to the printer is to prepare the job with your slicer, transfer the resulting job file to an SD card, then put that card in the printer and run the job locally. I'd rather not do that, since I'll lose the monitoring and feedback features of the software I use that way.
Anyway, off to find some drivers...I hope. :)

Searched and downloaded drivers from motherboard site. There really were only a few. I updated the chipset and audio drivers, but that's about it. The SATA drivers had to be installed from a floppy (!) and the RAID drivers weren't in exe package, so I didn't know what device to apply them to, since I don't have a RAID array on this system. Anyway, those updates did nothing, the driver for my 3D printer is still failing.
The farthest I've gotten so far is back to the point where if I put the driver.inf, driver.pnf, and usbser.sys files all in the same directory, then run the "update driver" option from devmgt, it will install the driver, but tell me it's corrupted and refuse to load it. I can post the setupapi.dev.log file if that will help.

saw this from an amazon review

"The drivers for the printer might not install automatically. To avoid headaches while installing the included driver (on the microSD card), you may need to disable driver signature verification. There are a number of tutorials online."

the monoprice tech guy that I quoted earlier seems to be saying that the drivers are on the SD card that came with the printer, and also that they are buried within in the cura software package.

He's correct, they don't install automatically.
I've already disabled driver verification, as noted above.
the Monoprice guy is customer support. They don't make this printer, they just sell it. Honestly, they don't really know much about it. The drivers aren't actually on the SD card at all, but are (as I explained above) supposed to be using the built-in windows drivers for USB->serial devices. What's on the SD card is a simple inf file to direct Windows which files to pull from it's catalog to install. This is what seems to be failing, but I can't seem to figure out where the failure actually is, and what I'm hoping to get some help with.
Does anyone know of a high-level support forum that specializes in driver troubleshooting/debugging? I think those folks would be able to help me decipher the logs and figure out what file(s) are missing or what it's choking on.