If you see Code 39 in Device Manager, Windows is unable to load the correct driver for your USB or related device. This usually happens after updates, registry corruption, or security conflicts. Follow these methods in order. If one method doesn’t work, move to the next.
Method 1 — Turn off Core Isolation (Memory Integrity)
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Open Settings → Privacy & Security → Windows Security → Device Security.
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Click Core isolation details.
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Turn Memory integrity Off.
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Restart the PC.
If not fixed, go to Method 2.
Method 2 — Delete UpperFilters / LowerFilters from Registry (very effective)
Be careful. Do not change or delete anything else.
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Press Win+R, type regedit, press Enter.
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Go to:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{36FC9360-C456-11CF-8056-444553540000} -
On the right side, find UpperFilters and LowerFilters.
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Right-click each → Delete.
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Close Registry Editor and Restart.
If not fixed, go to Method 3.
Method 3 — Rebuild USB Controllers from Device Manager
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Open Device Manager.
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Expand Universal Serial Bus controllers.
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Right-click and Uninstall every USB Root Hub, Generic Hub, and Host Controller.
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Click Action → Scan for hardware changes.
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Restart the PC.
If not fixed, go to Method 4.
Method 4 — Run Hardware Troubleshooter
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Press Win+R.
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Type:
msdt.exe -id DeviceDiagnosticand press Enter. -
Click Next and let it complete.
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Restart the PC.
If not fixed, go to Method 5.
Method 5 — Repair Windows System Files (SFC + DISM)
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Open Command Prompt as Administrator.
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Type:
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After it completes, in the same window type:
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Restart the PC.
Conclusion
Code 39 is usually caused by a conflict between Windows security, corrupted registry filters, or broken USB controller drivers. By turning off Memory Integrity, cleaning the UpperFilters/LowerFilters entries, rebuilding USB controllers, running the hardware troubleshooter, and repairing system files, you reset every layer that can cause this error. In most cases, these steps fix the issue completely without needing to reinstall Windows.
Common Q&A (Short)
Q1: What is Code 39 in Device Manager?
A driver loading failure caused by registry corruption or driver conflict.
Q2: Is it safe to delete UpperFilters and LowerFilters?
Yes, only in the specified registry path. Do not delete anything else.
Q3: Why uninstall all USB controllers?
Windows automatically rebuilds fresh drivers on restart.
Q4: What does SFC and DISM do?
They repair corrupted Windows system files and the Windows image.
Q5: If all methods fail?
Update chipset/USB drivers from your motherboard/laptop website or perform an in-place Windows repair.
