Some Windows users are seeing the “Not Enough USB Controller Resources” error when plugging in a device/peripheral inside the USB port. Most of the time, this is reported to occur with USB 3.0 ports. The issue is not specific to a particular Windows version as it’s reported on Windows 7, Windows 8.1 and Windows 10.
What is causing the “Not Enough USB Controller Resources” error?
We investigated this particular issue by looking at various user reports and the resolve strategies that most affected users have made use of to resolve the issue.
Based on our investigations, the issue is rarely related to power or bandwidth. Most likely, you’re encountering this error message due to an EndPoint limitation.
What is a USB endpoint?
An endpoint is the most basic form of USB communication. An endpoint will carry data in only one direction (either from the host computer to the device or vice versa). That’s why there are two types of endpoints (OUTs and INs).
When you connect a USB device, your computer will create a number of EndPoints (channels running to or from the device). Flash drives will use 3-4 endpoints, where headsets and other sensors might use up to 10 IN and OUT endpoints.
With this in mind, there are three major situations that can cause the “Not Enough USB Controller Resources” error:
- USB Controller limit is exceeded – If you use a lot of USB devices which are using a lot of EndPoints, you might see this error message because you’ve exceeded the available number of EndPoints. Keep in mind that USB 3.0 controllers have a limit of 96 Endpoints per controller on Intel XHCI controllers while AM4 controllers support 254 EndPoints.
- The USB port EndPoints usage exceeded the limit – Most USB controllers are capped at 16 IN & 16 OUT EndPoints for every available port. But since most devices will use primarily IN EndPoints, you’ll run out of them pretty quick. Because of this, you can only use USB ports to a limited extent.
- Power being drawn from the USB devices exceeds the maximum capacity – If you’re encountering this particular issue on a notebook or laptop, it’s very likely that the amount of power being drawn from the USB devices exceeds the maximum capacity. Using a docking station or a USB with its own power source will resolve the issue in this case.
If you’re encountering the “Not Enough USB Controller Resources” error and you’re looking for some methods that will allow you to resolve or circumvent the issue, this article will provide you with some troubleshooting guides.
Down below, you’ll find a collection of methods that other users in a similar situation have successfully used to get the issue resolved. To stay efficient, we advise you to follow the methods in the order that they are presented in.
Method 1: Moving some devices to a regular USB 2.0 port
If you’re encountering this issue on a USB 3.0 controller, you will be able to circumvent the error by moving some devices to the classic 2.0 port. If you’re trying to connect hardware that uses a lot of endpoints (VR headset, 7.1 headsets), you might be tempted to use a USB 3.0 hub to enjoy all the benefits that come with the newer transfer protocol.
But USB hubs can only be used for a limited degree since you will exceed the 16 IN Endpoint limit fairly quick (just by connecting a VR Headset + 7.1 Headset). Fortunately, you can go around this problem easy just by connecting one of your devices to a regular USB 2.0 port.
Try to leave the devices that need superior transfer speeds the most to the USB 3.0 port and move an older device to the USB 2.0 port.
As soon as you go under the 16 EndPoint limit, the “Not Enough USB Controller Resources” error should no longer occur.
Method 2: Using a docking station or USB Hub with its own power source
If you’re encountering this issue on a laptop/notebook, chances are the problem comes from the total amount of power being drawn from the USB ports.
If you can’t limit the number of the devices that are drawing power from your USB ports, you can resolve the “Not Enough USB Controller Resources” error by purchasing a docking station or a USB hub with its own power source (Powered USB Hub).
Docking stations are generally more expensive (over $50), so if you’re looking for a cheap workaround, you can easily find a Powered USB Hub a the $15 price mark.
Method 3: Reinstalling the Universal Serial Bus Controllers
As some users have reported, this particular issue can also occur if the USB controller driver was badly installed or got corrupted somehow. You might be able to resolve the “Not Enough USB Controller Resources” error by using Device Manager to reinstall the USB controller driver.
Here’s a quick guide on how to do this:
- Press Windows key + R to open up a Run dialog box. Then, type “devmgmt.msc” and press Enter to open up Device Manager.
- Inside Device Manager, expand the Universal Serial Bus controllers, right-click on your USB host controller and click Uninstall Device. If you have two different USB Host Controllers, uninstall both.
- Restart your computer. At the next startup, Windows will automatically reinstall the missing USB Host controller driver.
If the “Not Enough USB Controller Resources” error is still occurring, move down to the next method below.
Method 4: Disabling the XHCI Mode Option from BIOS setting
An extreme solution that will most likely resolve the “Not Enough USB Controller Resources” error with USB is to disable the xHCI Mode option from the BIOS Settings. But doing this automatically means that all your USB 3.0 ports are downgraded to USB 2.0.
If this is a sacrifice you are willing to make in order to resolve the error message, here’s how to disable the Intel xHCI Mode option:
- Restart your computer and repeatedly press the Setup key during the initial screen until to access the BIOS settings of your computer.
Note: The Setup key is typically shown on the initial startup key, but if you can’t see it, search online for specific steps on how to enter your BIOS settings (based on your laptop/motherboard model)
- Once you’re inside your BIOS settings, go to the Advanced tab and look for an option named USB EHCI debug under Device Options. Enabling this option will disable the xHCI controller which ends up resolving the error message.
Note: These settings will be different depending on your manufacturer. You might find this setting under a different name including XHCI Pre-Boot mode, EHCI Hand-OFF or xHCI Mode.
- Once xHCI controller has been disabled, save your modifications and allow your computer to boot up normally.
- At the next startup, you should no longer see the “Not Enough USB Controller Resources” error.