Download and Install CyanogenMod 11 Nightly for HTC One M7

Great day for all HTC One M7 device owners, the new CM 11 based on Android 4.4.3 KitKat is available for download. This step by step guide is provided to teach you how to install the new custom ROM on the HTC One M7 device.CM 11 Nightly ROM represents the latest custom ROM released by the CyanogenMod team for HTC One M7 Device and comes to offer the closest stock KitKat experience that you want from a custom ROM.
  Before you download and flash it on your device, you should first take a look on the preparation guide from below:

• This post is compatible with HTC One M7 GSM device, do not use the same for any other incorrect devices.
• Ensure that your smartphone has an unlocked bootloader (Here how to).
• Your HTC One M7 device has to be an rooted device and to have a custom Recovery Image installed on it like CWM or TWRP before starting to install the new custom ROM.
• Enable the USB Debugging option from Developer Options. As you, probably know that this will allow the user to easily transfer different files between PC and device.
• In this step by step guide you’ll take a Nandroid ROM Backup and a Factory Reset step, do not skip them. Backup installed applications, SMS text messages and all your data files by using suitable applications from Google Play Store such as Helium for Android.
• Be sure that you’ll sync all your Contacts data and information with your default Gmail account.
• Ensure that de device’s battery power level is more that 65%, and this will make your device to do not get a switching off in the middle of the flashing process.
• We Android Source team cannot be held liable or responsible for any data lost or bricking your device during or after installation process.
• Do not skip any steps from this tutorial.

How to install the CM 11 Android 4.4.3 Nightlies for HTC One M7:- 

•  Firstly, download the new CM 11 4.4.3 Nightly zip file from this link. (Download the latest Nightly build possible). Download the Gapps zip file for Android 4.4.x Here 
• Now by using the USB cord connect your PC and then copy both files to the device’s internal storage.
•  After the transfer is done, you can remove the USB cable from PC. Turn off the HTC One M7 device. Boot the device into Recovery Mode (here is how to). When the main menu of the CWM or TWRP recovery menu is displayed you can move to the next step.
•  Get a NANDROID Backup for the already installed OS (ROM), if you have a CWM recovery image then select “backup and restore, give a name to the file and then confirm this process. If you have the TWRP custom image press the “backup” button and rename the file and confirm the backup. 
• Now, apply a Factory Reset process, CWM (select “wipe data/ factory reset” and then Confirm, for TWRP press the Wipe and confirm the process.
•  Now flash the CM11 Android 4.4.3 Nightly custom ROM for your HTC One M7 device. If your device has a CWM custom recovery select the “Install Zip from Sdcard” and then select ”chose zip from sdcard”.
•  If your device has a TWRP custom recovery press, Install and then find the CM11 Nightly zip file and then load it, confirm for its installation. After the new custom CM 11 ROM has been successfully flashed you can install Gapps zip file as well. 
• Use the same steps as the previous steps. When you finalize the installation of the new CyanogenMod custom ROM you can reboot the One M7 device into normal mode. 
• The reboot will take a wile and you shouldn’t touch any buttons until the first home screen is displayed. Use the account information and then take control over the One M7 device. 

Congratulation, the new CM 11 Nightly custom ROM is successfully installed on the HTC One M7 device.