If you’re an owner of the LG Quantum/c900, you may have noticed that your carrier hasn’t enabled Internet Sharing on the device. This is a universal problem for all carriers with the exception of Telstra (Australia). Internet sharing is a feature that Microsoft made available in Mango, to carriers but not consumers. The drivers are available to manufacturers, who can choose whether or not to include them in their Mango drivers and can also be removed by carriers before pushing them out to the public. Now let’s go back to that bit about Telstra… It is true that this carrier selected to include the tethering drivers in their mango driver package. There was much speculation about changing registry values to get the update on a different carrier, but this would not work because of the model variations - the Telstra Quantum is labelled c900k, with the Bell variation being c900b, while AT&T and other international models are simply c900). There are actually no hardware differences between the two, so I’m unsure why they’re labelled differently. Now, in order to get tethering on any Quantum, we need to flash the Telstra ROM. If you’re uncomfortable with flashing ROM’s, or have never done it before (it’s easy, trust me!), you may want to stop here, although I have included easy instructions for newbies. Please note that flashing a ROM will delete/erase all content on your phone. You can reinstall apps more easily by viewing your purchase history in the Zune software! Alternatively, you can read how to enable wired tethering (which doesn’t require flashing) at the bottom of this post. **Note that this will break MMS! The only solution (at this time) is to carrier unlock your phone and run the LG Network Setup tool, available from the marketplace!** First of all, you’ll need to download the package (which weighs in at 372 MB) after the break, which has:A modified DLL that allows cross-model flashing.The LG flashing/engineering tool.The LG United Mobile driver.The Telstra Mango ROM Download this file (Deposit Files) and extract the contents to wherever you want. Start your phone in “Emergency Download” mode; you can do this by holding the camera and volume down button while pressing the power button. A screen with an exclamation mark should appear, with the text “EmergencyDownload”.On your PC, open the “LGDP2 V36 Flashing Tool” folder, followed by the “Setup” subfolder.Launch the included executable and proceed through the installation process. When asked for the serial key, copy and paste it from “Serial Number.txt”. Finish the setup. You may get an error related to mqmailoa.dll, disregard it.Copy the “DOWNLOAD” folder from the flashing tool folder and paste it in C:\, overwriting any file conflicts.Install the LG Modem Driver found in “LG Modem Driver (MA 4.9.7) in your extracted directory.Connect your phone to the computer via USB and allow the drivers to install.Disconnect your phone now.Navigate to C:\DOWNLOAD and launch “LGDP2_V36_UMTS.exe”The tool will launch with a pop-up asking for Model Division, select “UMTS” and press OK.You will be presented with another pop-up, asking for Port Selection. In “Easy Select” on the left hand side, select “All”. Under “DLL Selection”, point the program to the DLL located in the directory you originally extracted everything to, under subfolder “DLL”Under “Download Configuration”, point the program to the Telstra Mango ROM, which is also in the extracted directory, under ROM. Press OK. Ignore warnings about being “Unable to Find Monitor Port”.Press “START” in the upper right hand corner. DO NOT CONNECT YOUR PHONE YET!NOW reconnect your phone. The process will begin, allowing you to view detailed information related to the progress in whatever COM port window the phone is connected to. Be patient as the process may take some time. DO NOT DISCONNECT YOUR PHONE!When the progress reaches 100%, you may disconnect. Now quickly run through the setup of your phone. At this point in time, you can close the LG Flashing Tool.You’ve now officially flashed the ROM.There are still a few steps to get tethering! Currently, you are running Mango only. The latest LG/Telstra drivers haven’t been installed yet.Navigate to settings on your phone and verify “Date and Time” are set to the correct values, and set “Region and Language Options” to the appropriate values for where you reside and tap “Accept Changes and Restart Phone” at the top.Reconnect your phone to your computer and launch Zune. If required, go through a quick name setup and then allow the phone to check for updates. The update “LG Update for Windows Phone” will be installed. After this, restart your device and voila! You can now enable Internet Sharing from the Settings menu! Telstra has also released the 8107 update, so you don't have to use the CAB sender method to get the keyboard fix. If you want to remove the Telstra boot screen (or even replace it with your own), you can root unlock your device using WP7 Root Tools 0.9 (requires interop unlock first: see here (follow the LG method, obviously) http://forum.xda-developers.com/showthread.php?t=1271963, and then use this tool http://windowsphonehacker.com/articles/app_wph_tweaks-04-09-12 If you’re uncomfortable with ROM flashing, or don’t want to have to re-sync your content/apps, there is a less efficient but easier to apply method of tethering via USB. This hack is applied via the LG MFG app on the phone, but requires a reboot every time you apply it. To do this, follow these instructions:Install the LG Pilot Modem Driver from here! (Deposit Files).Open the dialpad on your phone and dial “##634#”. The MFG app will install and open.You’ll be presented with a password field. The password is “appmfg#*#”.Open the “Engineer Menu” and then “Port Setting” followed by “USB Switching”.Take note that the default value here is MS COMPOSITE” - if you don’t change this back later, you’ll be unable to sync your phone via USB with Zune.Select “QC COMPOSITE” and press OK to reboot.Connect your phone to your PC, the drivers will be automatically installed.Open Device Manager, and find “LGE CDMA USB Modem” and open the Properties dialog. Under the advanced tab, add the additional string “AT+CGDCONT=1 “IP” “your carriers APN” (isp.cingular for AT&T, “pda.bell.ca” for Bell Canada, etc). Apply the setting.Create a new connection, by opening start and typing “dial-up”, click “Setup a Dial-up Connection”Select the “LGE USB Modem” as the source, and set the phone number as either *99***1# (America/International[?]) or *99# (Canada).Turn off the Data connection on your phone prior to dialing!Connect! There’s no username/password.The next time you want to sync via USB, you need to change back to MS COMPOSITE in MFG.