Recently i had written article about Huawei D100 O2 Surf Station (Germany). Huawei D100 wifi router gateway is different than other USB modems and routers. Huawei D100 gateway needs USB modem to use it.
Like another WiFi Routers, Gateway and Modems Huawei D100 can also be unlocked. But, unlocking of Huawei D100 Router Gateway is different than the Huawei USB modems and routers. Huawei D100 Router Gateway can not be unlocked with card lock unlock tool or Huawei modem code writer tool, because Huawei D100 Router Gateway has no USB port. Huawei D100 Router Gateway comes with LAN ports. But, Huawei D100 Router Gateway can be unlocked with FMC unlocker tool. FMC Unlocker tool / Software can be downloaded from the download link which is provided at the end of the article.
To unlock your D100 Huawei WiFi Router Gateway, connect via RJ45 cable to PC and close all the running software. Now run FMC unlocker software and detect your device under that. Now when D100 imei will be visible in FMC unlocker software then put unlock code of D100 Huawei WiFi Router Gateway and click on unlock and you have successfully unlocked your D100 Huawei WiFi Router Gateway. Now dance around the room and use any another network provider sim on it.
If your D100 Huawei WiFi Router Gateway is of customised firmware then you can use unlocked firmware version 396.11.133.04.112 14-JAN-2010, branded by DNA Finland or unlocked firmware version 396.11.147.05.111 6-JAN-2010, branded by ERA Poland or unlocked firmware version 396.11.16.06.109 22-JULY-2009, branded by DNA Finland or unlocked and unbranded firmware version 396.11.00.09.108 01-JUNE-2009.
Update: Refer this guide to unlock Huawei D100/D100T routers.