While the highly anticipated Jelly Bean 4.1 update has already started rolling out for the HTC One S, users now have the option to notch the update a step up compared to what they are currently getting via the official rollout.

The HTC One S as well as HTC One S special edition can now be upgraded to latest Android 4.2.1 Jelly Bean with the help of custom ROM CM10.1. The HTC One S already comes with Android 4.0 ICS out of the box and sports a dual-core 1.5 GHz Krait processor alongside a 1GB RAM, and this specification is more than enough to run the new Jelly Bean 4.2.1.

While the version 4.2.1 comes with many custom tweaks and features, it should be noted here that this CM10.1 ROM for HTC One S is still under development and could contain a few bugs and issues, accordingly. However, all the issues will be fixed as the development progresses.

Before heading on to the original steps, it is important to remember that these steps are only for HTC One S and it is not advisable to apply the same on any other Android device. It is important to backup the data before following the steps.

To perform the steps, the device needs to have at least 80 percent battery left in it, and that the USB driver for HTC One S is already installed in the PC. It is also important to make sure that the USB debugging has been enabled with the bootloader unlocked. The device also needs to be rooted and have ClockworkMod Recovery installed.

The following steps are to be tried at the user's own risk and Mobilenapps shall not be held responsible for any related damages that may or may not occur while the steps are being implemented. Users are advised to follow them at their own risk.

Here are the steps to install Android 4.2.1 Jelly Bean CM10.1 ROM:

• Step 1:To begin, connect the HTC One S to PC using USB cable.
• Step 2:Copy downloaded zip file to the SD card of the phone. Remember not to extract any file here. (All related download files can be found below)
• Step 3:Now disconnect USB and turn off the phone.
• Step 4:Here users will need to boot into recovery mode. For that, press and hold Volume Down and Power button together to boot into HBOOT menu, from there select Recovery [use volume buttons to scroll and Power button to select]. Users can also try this as an alternative:Recovery Mode without Key Combination.
• Step 5:Now perform a Nandroid backup of the existing ROM that can be restored later if this new ROM doesn't work or if the user wants to go back. To perform a backup, select Backup and Restore, and then on the next screen, select Backup again. Head back to main recovery menu after backup is done.
• Step 6:Next, perform the data wiping task. To do so, select wipe data/factory reset, then select Yes on next screen to authenticate the action. Now wait few minutes till the data wipe is successfully completed.
• Step 7:Select install zip from sdcard, and then select choose zip from sdcard. Now, find the cm-10.1-20121224-UNOFFICIAL-ville.zip file that was copied earlier in Step 2 and select it by pressing Power button. Users will need to confirm the installation by selecting Yes - Install _____.zip on the next screen. The ROM installation will now begin.
• Step 8:Once the ROM installation process ends, repeat step 7 but instead choose gapps-jb-20121212-signed.zip instead of ROM zip to install the Google apps package.
• Step 9:When installation is finished, go back to the main recovery menu and select reboot system now in order to reboot the smartphone and boot up into customized Android 4.2.1 ROM. The first boot will take a bit of time.
• Step 10:To return to Previous ROM, users will need to go back to the previous ROM, boot into recovery, select backup and restore, and then restore the previous ROM by selecting it from the list. That should be it.

Download Links:

• Android 4.2.1 CM10.1 ROM for HTC One S[Filename: cm-10.1-20121224-UNOFFICIAL-ville.zip]
• Google Apps[Filename: gapps-jb-20121212-signed.zip]

It is to be remembered that this CM10.1 release, per an Android Jinn report, "is not an official CyanogenMod Team release."