One MaximuS is a custom ROM for the HTC One S based on the official firmware version 1.78.401.2, by XDA developer Football. The ROM is quoted to have the best performance and excellent battery life, and also has no bloatware aka unnecessary stock apps.

Here’s a look at some of the other features of the ROM:

  • RAM optimizations
  • Working HTC Hub app
  • Fast and Smooth UI
  • Ability to choose any language you want
  • Deleted feedback apps
  • All apps updated

So, without waiting any further, let’s take a look at how the One MaximuS ROM can be installed on the HTC One S.

Compatibility

This guide is applicable only for HTC One S. DO NOT try this on any other device.

Warning!

The methods and procedures discussed here are considered risky and you should not attempt anything if you don’t know completely what it is. If any damage occurs to your device, we won’t be held liable.

How to Install One Maximum ROM

  1. This procedure will wipe all your apps, data and settings (but it will NOT touch your SD cards, so don’t worry about those). Backup your Apps and important data — bookmarks, contacts, SMS, APNs (internet settings), etc. This Android backup guide would help you.
    Important! Don’t forget to at least make a backup of your APN settings, which you can restore later if your data connection does not work after installing the ROM. Use the backup guide to find out how.
  2. Unlock the bootloader on your One S and install Clockworkmod (CWM) recovery as well. You can use the HTC One S All-in-One Toolkit here to unlock the bootloader as well as install CWM recovery.
  3. Download and install HTC Sync software on your computer in order to install the required drivers for the phone.
    Download HTC Sync
    Skip this step if you already installed the drivers while following step 2.
  4. Download the latest version of the ROM from the official development page.
  5. Copy the downloaded zip file of the ROM (don’t extract it) to the SD card.
  6. Also download the latest version of the Android Fastboot Kit from the official download page linked in step 4. The download link can be found at the bottom of the official page. You’ll get a .rar file after downloading.
  7. Extract the .rar file using a software like WinRAR or 7-zip to a convenient location on your computer to get a folder named Android.
  8. Now, turn off your phone, then boot into bootloader mode by pressing and holding down the Volume Down + Power keys together. Here, highlight Fastboot by using the volume keys then select it using the Power button to enter fastboot mode. Then, connect the phone to the computer.
  9. Go to the Android folder obtained in step 7. Double-click the Install Boot.img.bat file to flash the kernel.
  10. After the kernel is flashed, the window that showed up will automatically close.
  11. Now, on your phone, highlight HBOOT using the Volume +/- buttons then select it using the Power button. And then select RECOVERY to boot into recovery mode.
    Use volume buttons to scroll up and down and the power button to select options in bootloader menu and recovery.
  12. Select wipe data/factory reset, then select Yes on the next screen to confirm data wipe. This will only delete your installed apps and settings, but will leave all other files and data on the SD card intact, so don’t worry.
  13. Then, select install zip from sdcard, then select choose zip from sdcard. Scroll to the ROM file on the SD card and select it. Confirm installation by selecting Yes – Install _____.zip on the next screen.
  14. After installation is complete, select go back then select reboot system now to reboot the phone and boot up into MIUI ROM.

The One Maximus ROM is now installed on your HTC One S. Visit the official development page for more information and to get the latest updates on the ROM. Share your thoughts on the ROM in the comments below.