As Microsoft acknowledged in the known issues section of monthly rollup KB4480970, this update causes the network interface control to stop working, leading to a possible full loss of network connection.
“After you apply this update, the network interface controller may stop working on some client software configurations. This occurs because of an issue related to a missing file, oem.inf. The exact problematic configurations are currently unknown,” Microsoft says.
This is the only known issue in monthly rollup KB4480970 for Windows 7.
As Windows 7 IT admins and long-time Microsoft watchers probably know, this isn’t a new bug, and it was, in fact, part of nearly every single monthly rollup published in the last 12 months.
The first time it was acknowledged by Microsoft was on March 13 when the company released monthly rollup KB4088875 for Windows 7. Since then, the issue existed in every single release, and for some reason, the software giant has never fixed it in the newer updates.
While this is certainly bad news, many believe this is actually a strategy embraced by Microsoft especially because we are getting closer to the end of support for Windows 7. I highly doubt this is the case, but if you’re still running Windows 7, you should consider upgrading, as the January 2020 end-of-support date is indeed approach and staying on this OS version without security patches is quite a risky thing to go.
Returning to the network issue, the same problem may be caused by update KB4480970.
And just like before, Microsoft says you can manually resolve the problem by reinstalling the network adapter on your device.
Technically, this shouldn’t be such a troublesome task for the majority of users, but it goes without saying that it’s not very convenient for beginners to do this, especially because working with the Device Manager isn’t exactly a straightforward thing to.
What you need to do is open the Device Manager tool by pressing the Windows key + R and then typing devmgmt.msc.
If your system lost the network connection, there’s a chance that your network adapter is no longer displayed under the Network section. So look in the Other Devices category (double-click to expand and see all devices listed here).
Once you locate the network device, you can just right-click it > Update. During the wizard, select the option that reads Search automatically for updated driver software. If the network device drivers are located on your system, you can also point the setup to these files using the Browse my computer for driver software option.
As an alternative, you can just click Actions > Scan for hardware changes, and if you’re lucky enough, Windows 10 should detect that your network device was uninstalled and automatically install it once again.
And last but not least, if you already backed up the drivers on the local drives, on a disc, or on an external drive, you can just install them once again using the provided installer. This replaces all the steps above and basically helps set up the network interface controller once again. In this case, following all the steps above is no longer required.
In most of the cases, the network connectivity should be restored without a system reboot, but if this doesn’t happen, restarting the machine could help. For now, it’s not yet clear how many devices are affected by this issue, but given it’s been around for a while, Microsoft would really do everyone a favor if it decides to release a fix.