Unlocking a Huawei E1750 3G Dongle

This technique may work for other models, but I only own the E1750 and worked perfectly for me.

First thing you need is a IMEI number. If like me if you don't have the original box or paperwork, it's not that difficult to find it on a Windows machine

1. Install the drivers and the dongle onto a machine.
2. Find the modem in device manager.
3. If you look at the properties of the device, there should be a Diagnostics Tab (at least on Windows 7).
4. Click on Query Modem. One of the values returned will be the IMEI number.

Now that you have that, go to this web site http://tools.texby.com/unlock-codes/huawei/?download-huawei-code-writer.
This should return two codes. First is the unlock code, which you need to unlock the modem.
If you wish to upgrade the firmware, you need the next code and download the latest firmware, drivers and generic dialler software from here http://huaweiunlocking.blogspot.co.uk/2012/02/huawei-e1750-unlock-update-firmware.html.

As an addition, if you want to change the way the dongle is presented every time it is plugged into a computer, follow these instructions http://www.androidtablets.net/forum/gome-flytouch-ii-accessories/4686-my-manual-huawei-usb-3g.html.