# Impossible to get AT port in Win11 for EM7455 **URL:** \ **Category:** MC/EM Series\ **Created:** [September 10, 2025, 11:14am UTC](https://forum.sierrawireless.com/t/impossible-to-get-at-port-in-win11-for-em7455/35493 "2025-09-10T11:14:23Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![clement](https://avatars.discourse-cdn.com/v4/letter/c/7ba0ec/32.png) [@clement](https://forum.sierrawireless.com/u/clement)\ **Post date:** [September 10, 2025, 11:14am UTC](https://forum.sierrawireless.com/t/impossible-to-get-at-port-in-win11-for-em7455/35493/1 "2025-09-10T11:14:23Z")
Hello, I am writing on the forum after many tests without success. I am trying to get the COM port in AT mode but I can’t get it on the EM7455, on Ubuntu I have it without issues, via USBCOMP=6 or 8. The 6 or 8 makes no difference on Win11, no AT port in sight… I tried updating the drivers but it doesn’t change anything. I attempted to extract the file “GenericDriverSetup\_Build4581.exe” to modify the .ini file inside, but there is no .ini file inside. If I click on modem and advanced properties, there is no COM port displayed. ![image](https://us1.discourse-cdn.com/flex025/uploads/sierrawireless/original/2X/6/6909b98035e7534dfed699d5896ccfef83a2b71a.png) state of periph: This device cannot start. (Code 10) {The operation failed} The requested operation could not be completed. ![image](https://us1.discourse-cdn.com/flex025/uploads/sierrawireless/original/2X/d/d2d9e7816ecf839b54efce49ec67818c21e31970.png) ---
**Author:** ![jyijyi](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.sierrawireless.com/jyijyi/32/4766_2.png) [@jyijyi](https://forum.sierrawireless.com/u/jyijyi)\ **Post date:** [September 10, 2025, 12:24pm UTC](https://forum.sierrawireless.com/t/impossible-to-get-at-port-in-win11-for-em7455/35493/2 "2025-09-10T12:24:26Z")
how about this driver? [https://source.sierrawireless.com/resources/airprime/software/airprime-em\_mc-series-windows-drivers-qmi-build-5087/#sthash.N4Le3yIo.dpbs](https://source.sierrawireless.com/resources/airprime/software/airprime-em_mc-series-windows-drivers-qmi-build-5087/#sthash.N4Le3yIo.dpbs) You also need to set up the configuration.ini with USBCOMP=8: > [@USSD Software for Windows 10](https://forum.sierrawireless.com/t/ussd-software-for-windows-10/25041/36): > > you can open Configuration.ini and change “USBCOMP=8” and run the driver setup again ---
**Author:** ![clement](https://avatars.discourse-cdn.com/v4/letter/c/7ba0ec/32.png) [@clement](https://forum.sierrawireless.com/u/clement)\ **Post date:** [September 10, 2025, 1:23pm UTC](https://forum.sierrawireless.com/t/impossible-to-get-at-port-in-win11-for-em7455/35493/3 "2025-09-10T13:23:15Z")
I have this on the configuration.ini I put =8 ![image](https://us1.discourse-cdn.com/flex025/uploads/sierrawireless/original/2X/9/9a98f85a33fea4b593c5f3e1ee3559ac81854902.png) I made a folder like that: ![image](https://us1.discourse-cdn.com/flex025/uploads/sierrawireless/original/2X/b/b16e116bf55689164a2f79e82164429b951911df.png) And lauch the .exe : ![image](https://us1.discourse-cdn.com/flex025/uploads/sierrawireless/original/2X/d/d4082a89a7ee18b66c1105fbdaaafbcd1f5b6cd5.png) Installation finish with success message. But nothing change here: ![image](https://us1.discourse-cdn.com/flex025/uploads/sierrawireless/original/2X/1/1b5889e7104ea9ebd8a51f6cc55cc3ff7262c254.png) ![image](https://us1.discourse-cdn.com/flex025/uploads/sierrawireless/original/2X/3/3c69ea753c393515c0bb7fd57ab56e934f3094bc.png) ---
**Author:** ![clement](https://avatars.discourse-cdn.com/v4/letter/c/7ba0ec/32.png) [@clement](https://forum.sierrawireless.com/u/clement)\ **Post date:** [September 10, 2025, 1:24pm UTC](https://forum.sierrawireless.com/t/impossible-to-get-at-port-in-win11-for-em7455/35493/4 "2025-09-10T13:24:30Z")
![image](https://us1.discourse-cdn.com/flex025/uploads/sierrawireless/original/2X/8/86aabb6bb740f1017637f9e4581fc639a585abf5.png) ---
**Author:** ![jyijyi](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.sierrawireless.com/jyijyi/32/4766_2.png) [@jyijyi](https://forum.sierrawireless.com/u/jyijyi)\ **Post date:** [September 10, 2025, 1:38pm UTC](https://forum.sierrawireless.com/t/impossible-to-get-at-port-in-win11-for-em7455/35493/5 "2025-09-10T13:38:34Z")
is this a Dell PC? Seems to be similar issue as this one: > [@MC7430 firmware update](https://forum.sierrawireless.com/t/mc7430-firmware-update/30414/25): > > I tried to install but it won’t install, error code 10. ---
**Author:** ![clement](https://avatars.discourse-cdn.com/v4/letter/c/7ba0ec/32.png) [@clement](https://forum.sierrawireless.com/u/clement)\ **Post date:** [September 10, 2025, 1:41pm UTC](https://forum.sierrawireless.com/t/impossible-to-get-at-port-in-win11-for-em7455/35493/6 "2025-09-10T13:41:21Z")
No I use an adaptator. The chip is from a Lenovo I use a PC not dell or levovo. ---
**Author:** ![clement](https://avatars.discourse-cdn.com/v4/letter/c/7ba0ec/32.png) [@clement](https://forum.sierrawireless.com/u/clement)\ **Post date:** [September 10, 2025, 1:42pm UTC](https://forum.sierrawireless.com/t/impossible-to-get-at-port-in-win11-for-em7455/35493/7 "2025-09-10T13:42:19Z")
The modem works well, but the AT port does not open and I absolutely need it on Windows. ---
**Author:** ![jyijyi](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.sierrawireless.com/jyijyi/32/4766_2.png) [@jyijyi](https://forum.sierrawireless.com/u/jyijyi)\ **Post date:** [September 10, 2025, 1:54pm UTC](https://forum.sierrawireless.com/t/impossible-to-get-at-port-in-win11-for-em7455/35493/8 "2025-09-10T13:54:51Z")
could it be working in another USB port? Do you have VMWare Ubuntu image? You can route the USB to it and see if it can communicate with AT commands Lastly, there could be a chance that there is whitelist modem list in your PC: > [@Sierra EM7355 Not working on Lenovo P50](https://forum.sierrawireless.com/t/sierra-em7355-not-working-on-lenovo-p50/23036/5): > > I assume you’re getting that message printed by the BIOS itself, so there is no point in attempting to install any Windows drivers from anywhere, as the system is not even booting. The problem seems to be that the EM7355 isn’t listed in the Lenovo P50 whitelist of WWAN modules. See, manufacturers don’t want you to install any kind of WWAN module in the laptops, they have a device whitelist that says which WWAN modules you can install, and the whitelist is hardcoded in the BIOS so you cannot c… ---
**Author:** ![clement](https://avatars.discourse-cdn.com/v4/letter/c/7ba0ec/32.png) [@clement](https://forum.sierrawireless.com/u/clement)\ **Post date:** [September 10, 2025, 2:12pm UTC](https://forum.sierrawireless.com/t/impossible-to-get-at-port-in-win11-for-em7455/35493/9 "2025-09-10T14:12:14Z")
I have a ubuntu server and the AP port is open on it without problem. I built my own PC with a high-end MSI motherboard. Damn, I’m running out of solutions 😕 Do you know of any 4G modules that I could connect via USB like the 7455, which is easier to set up for using the AT port? In 2G, I’m already using the M26 from Quectel. ---
**Author:** ![jyijyi](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.sierrawireless.com/jyijyi/32/4766_2.png) [@jyijyi](https://forum.sierrawireless.com/u/jyijyi)\ **Post date:** [September 10, 2025, 2:25pm UTC](https://forum.sierrawireless.com/t/impossible-to-get-at-port-in-win11-for-em7455/35493/10 "2025-09-10T14:25:40Z")
you can try other modules: > **[4G Broadband Modules](https://www.sierrawireless.com/iot-modules/4g-modules/)** > > We offer the most comprehensive, consistent and rich set of APIs from the edge to the cloud to simplify your 4G Module. Learn more today! But i am not sure if your PC will have same problem. BTW, what do you want to set for the AT command? I am wondering if you can set it by skylight tool: > **[Skylight Windows Connection Manager for EM/MC series modules](https://source.sierrawireless.com/resources/airprime/software/airprime-em_mc-series-connection-manager/#sthash.WVyQUQHr.dpbs)** > > Skylight Windows Connection Manager for EM/MC series modules