B420-SR Unified Wire Ethernet Controller Driver 4.3.8.1
by ChelsioWindows 11Windows 1064-bitSHA-256 verified
- Manufacturer
- Chelsio
- Device
- B420-SR Unified Wire Ethernet Controller
- Driver version
4.3.8.1- Release date
- February 14, 2013
- Supported Windows
- Windows 11, Windows 10
- Architecture
- 64-bit (x64)
- File size
- 4.1 MB
- File name
20543580_62f7b119a125c7cd6ffa4efc069d4a13d8ac6e34.cab- Digital signature
- Signed - catalog
ChT4Ndis.cat - INF version
02/14/2013,4.3.8.1- INF provider
- Chelsio
- Device class
- Net
- Source
- Microsoft Update Catalog
- Last verified
- July 8, 2026
- SHA-256
d1c971048444f7a38db14b29de9c6e7718dc2186fee1bb96943171d3679489a5
Supported hardware IDs (3)
Compare with your device: Device Manager → right-click the device → Properties → Details → Hardware Ids. If one of the values above matches, this driver supports your hardware.
How to install
- Create a restore point(Start → "Create a restore point" → Create), so you can roll back if anything goes wrong.
- Verify compatibility: your Windows version (Windows 11, Windows 10) and architecture (x64)must match this driver, and your device's Hardware ID should appear in the list above.
- Download the file using the button - it comes directly from Microsoft Update Catalog.
- Optionally verify the checksum: open PowerShell, run
Get-FileHash your-download.cab -Algorithm SHA256and compare with the SHA-256 above. - Extract the .cab archive: right-click → Extract All, or run
expand -F:* file.cab C:\driver\in Command Prompt. - Install via Device Manager: right-click your device → Update driver → Browse my computer → point to the extracted folder. Alternatively run
pnputil /add-driver C:\driver\*.inf /install. - Check Device Manager: the device should show no warning icons, and the driver version should match.
How to roll back
If the device stops working after the update: Device Manager → right-click the device → Properties → Driver tab → Roll Back Driver. If the button is greyed out, use the restore point from step 1 (Start → "Recovery" → Open System Restore).