If Remote Desktop suddenly stopped working for a standard user after a Windows update, the error may not be caused by the account or password. Microsoft has fixed a specific connection fault in Windows 11 versions 25H2 and 26H2.
The fault can show error 0xC000000D with the message, "The token that was passed to the function is invalid." It is a narrow issue, but an awkward one for a small business when staff need remote access to a managed PC.
Which computers are affected?
Microsoft says the problem began after the September 22, 2026 non-security preview update, KB5124010, or a later update. It affects non-admin users connecting by Remote Desktop to enterprise-managed computers where Administrator protection is enabled.
Microsoft lists Windows 11 versions 24H2, 25H2, 26H1 and 26H2 as affected clients. Windows Server is not listed as affected. A failed connection on a home PC, or one showing a different error, may have another cause.
This distinction matters. Do not assume every Remote Desktop failure is this Windows fault, and do not change passwords or rebuild a user profile merely because the connection stopped after an update.
The fix for Windows 11 25H2 and 26H2
Microsoft marked the issue as resolved on October 28, 2026. The fix for Windows 11 versions 25H2 and 26H2 is in the non-security preview update KB5127936, which installs OS Builds 26200.9818 and 26300.9818 respectively.
On an affected PC, an administrator can check Settings > Windows Update for the preview update. Business-managed devices may receive updates on a set schedule, so check the organisation's update policy before installing it manually. Test the Remote Desktop connection again after installation and restart if Windows requests one.
Microsoft's earlier workaround was to temporarily turn off Administrator protection through Microsoft Intune or Group Policy. That weakens a security control, so it should not be the first step now that a fix is available for 25H2 and 26H2. If a business used that workaround, its IT administrator should review the policy and restore the intended protection after confirming the update has fixed the connection.
Checks before changing anything
First, confirm the Windows version by opening Settings > System > About. Then note the exact Remote Desktop error and check whether the person connecting uses a standard account rather than an administrator account.
Also check whether the remote computer is managed through Intune or Group Policy and whether Administrator protection is enabled. If those details do not match, look for another cause such as a network, VPN, firewall, account-lockout or Remote Desktop configuration problem.
Avoid removing security software, opening Remote Desktop directly to the internet or switching off protection settings without a plan to restore them. Those changes can create a bigger problem than the original connection fault.
When support is useful
A small business may need help if it cannot identify which machines have the affected update, if KB5127936 is not offered, or if users still see 0xC000000D after updating. This is also a sensible point to check Remote Desktop exposure, update policy and access permissions rather than applying the same workaround to every PC.
PC Repairs Barnstaple can help with [business IT support](service:business-it) and, where appropriate, [remote support](service:remote-support) for Windows update and connection faults.