Error 0x801901F4 in Windows Update and Store

Windows Update and the Store app may display the error code 0x801901F4 on some ASUS systems. Error code 0x801901F4 (HTTP_STATUS_SERVER_ERROR 500) usually occurs when you attempt to open a website with a malformed address or the URL has reserved characters.

Resetting Windows Update or resetting the proxy settings does not resolve the issue.

Cause

The “System Model” name on some ASUS ZenBook and VivoBook systems have the suffix _<!DOCTYPE that may have been added inadvertently during production.

You can see that by opening the System Information Utility (msinfo32.exe).

“<!DOCTYPE” is for declaring HTML document type and is used only on webpages. Not sure how it ended up in the System Model field in the firmware.

Due to this, Windows Update uses a malformed URL and encounters HTTP error 500 (“HTTP_STATUS_SERVER_ERROR”). If you run Get-WindowsUpdateLog in PowerShell and analyze the WindowsUpdate.log file, you’ll see entries similar to the following:

9404  10056 SLS   Retrieving SLS response from server...
9404  10056 SLS   Making request with URL HTTPS://slscr.update.microsoft.com/SLS/{9482F6B4-E363-43B6-B270-9A65BC822D77}/x64/10.0.22621.525/0?CH=234&L=en-US&P=&PT=0x30&WUA=922.728.511.0&MK=ASUSTeK+COMPUTER+INC.&MD=ZenBook+UX393EA_%3C!DOCTYPE and send SLS events.
9404  10056 Misc  StatusCode for transaction returned from WinHttpQueryHeaders is 500
9404  10056 Misc  *FAILED* [801901F4] WinHttp: SendRequestToServerForFileInformation (retrying with default proxy)

So, instead of accessing the following URL:

Windows Update tries to access the following and encounters the error 0x801901F4:

Due to this, Microsoft Store also causes the same error.

Resolution

It’s an ASUS issue. The invalid System Model text embedded into the UEFI causes Windows Update to fail and throw the error code 801901F4.

You can read more about it in the links below.

Cannot get Windows Update / Microsoft Store working
byu/Ok_Reputation_3743 inASUS

Changing (Fixing) System Model in ZenBook BIOS/UEFI
byu/saltycrumb inASUS

Unless you want to third-party flash tools like DMIEDIT (which may void the warranty), please contact official ASUS support to see if there is a firmware update for this issue.

Please see the queries posted by some user at the ASUS support forum.

Windows update and Microsoft store not working – Republic of Gamers Forum – 993639

ZenBook S 13 UX393EA – Windows Update & Microsoft – ASUS – ZenTalk – 356679