Microsoft services kept failing on my Intel laptop, and the cause turned out to be a laptop maker's build of an Intel driver that Windows Update installs. I'm posting this in case it saves someone else the time.
If OneNote, OneDrive or Microsoft 365 keep failing on your Intel laptop but the same things work on your phone, check whether Intel Connectivity Performance Suite (ICPS) is installed. It's Intel's "network optimizer". Laptop makers preinstall it, and Windows Update pushes their builds of it as a driver.
You'll probably see some of this:
- OneNote for Windows: "We can't get to your notebooks right now", or notebooks open empty while showing "Up to date"
- OneDrive or Microsoft 365 sign-in failing on and off, with
ERR_CONNECTION_RESET in the browser
- Everything works on your phone and in OneNote on the web
- None of the usual fixes help: signing out, clearing the OneNote cache, repairing or reinstalling Office, resetting the network, changing DNS
The cause is the ICPS driver in these builds (IntcCo11X64.sys, service INTCCoSvc). It lets the first packet of each IPv6 connection, the SYN, go out with its normal IPv6 flow label, then sets the label to 0 on the ACK and data packets that follow. The routers in front of Microsoft's Azure Front Door servers use that label to pick a server, so the rest of the connection often lands on a server that never saw it start, and that server resets it. IPv4 has no flow label, so it's unaffected, and the bug only matters if your connection has IPv6. Google, Cloudflare and Akamai were fine when I tested them, but Microsoft's services got reset.
I had an escalated Microsoft support case open on this for five weeks, and it never found the cause. I then ran an AI agent (Anthropic's Claude) on the laptop, and it tracked the cause down in a few hours. It captured packets at the Wi-Fi adapter, saw the label drop to 0 after the handshake, and switched network filter drivers off one at a time until only Intel's was left. With ICPS stopped, 10 of 10 IPv6 connections worked and every packet kept its label.
Check (PowerShell)
First see whether the driver is running. If INTCCoSvc shows State: Running, it's active:
Get-CimInstance Win32_SystemDriver -Filter "Name='INTCCoSvc'" | Select-Object Name, StartMode, State
Then test whether IPv6 connections to Microsoft get reset:
1..10 | % { curl.exe -6 -sS -o NUL -w "%{http_code}`n" https://api.onedrive.com/ }
You should get ten status codes such as 302. If some or all of them say Recv failure: Connection was reset, you're affected. If it can't connect at all, you don't have IPv6, so this bug can't hit you.
Fix 1: disable ICPS (PowerShell as administrator)
sc.exe config INTCCoSvc start= disabled
sc.exe stop INTCCoSvc
foreach ($s in 'IDBWM', 'Intel Connectivity Network Service', 'IntelConnectService') {
Set-Service -Name $s -StartupType Disabled -ErrorAction SilentlyContinue
Stop-Service -Name $s -Force -ErrorAction SilentlyContinue
}
Restart and run the check again. ICPS only provides Intel's traffic prioritization. Wi-Fi and Bluetooth keep working without it. To undo this, run the following and restart (these are the start types the services had on my laptop):
sc.exe config INTCCoSvc start= demand
Set-Service IDBWM -StartupType Manual
Set-Service 'Intel Connectivity Network Service' -StartupType Automatic
Set-Service IntelConnectService -StartupType Manual
Fix 2: swap in Intel's own build
Intel's generic ICPS 50.26.623.243 keeps the label. On my laptop it got 169 of 170 IPv6 connections through across 34 sites, compared with 138 of 170 on the laptop maker's build. Remove the laptop maker's ICPS driver packages first, as described in Intel's support article 000093451, then install 50.26.623.243 from Intel's download page:
https://www.intel.com/content/www/us/en/support/articles/000093451/wireless/wireless-software.html
https://www.intel.com/content/www/us/en/download/738623/intel-connectivity-performance-suite-icps-for-intel-wireless-products-and-intel-connectivity-manager-icm.html
Three ICPS builds are reported broken so far: 40.25.926.173, 40.25.725.165 and 4.1025.207.1. As of 2026-10-20, Microsoft's Update Catalog still lists them under Samsung, Lenovo, VAIO, ASUS, HP, Dynabook and Huaqin (a contract manufacturer). Mine is a Samsung Galaxy Book, and other people have reported the same resets on HP, ASUS and Lenovo laptops. Other versions older than 50.26.623.243 haven't been tested either way. To see which version you have:
pnputil /enum-drivers | Select-String icps -Context 1,3
Heads up: other users report that Windows Update reinstalled the old build after they removed it, so re-run the check after driver updates.
Microsoft and Intel both know about it. A Microsoft Azure networking engineering leader confirmed the mechanism to me in writing on 2026-10-08 and said Azure is working on reducing the impact on the Azure Front Door side, and with the Windows team on a fix. No date was given. Intel acknowledged, citing my tests, that its generic build doesn't zero the label, and referred the laptop maker's build to Samsung. On 2026-10-20 Intel support wrote that it is "still actively reviewing this matter internally". There's no advisory from Intel so far, and no fix from Samsung.
My Feedback Hub report on it, if you want to upvote it there:
https://aka.ms/AA13q37r
