When u try to update the kk, it fails at like 40% and ur hboot is upgraded. Use this guide for zara-cl if ur hboot is 2.22 (kk)
If you have the different partition layout that was introduced with the KitKat update, and also have the upgraded HBOOT then I guess i'll write up this guide. To get the phone back in proper working order, you need to do this.
1) Make sure you have the HTC drivers installed, and HTC Sync Manager fully uninstalled. ADB/Fastboot and such in working order, etc.
2) Download the KitKat OTA ZIP from Duir's Drive Folder here https://drive.google.com/uc?id=0B-kS...xport=download
and open it up and take out firmware.zip
3) Get into HBOOT on the phone, and flash that firmware.zip file by running fastboot flash zip firmware.zip and also run fastboot flash update firmware.zip both will say FAIL but for me that worked if that didn't work then relock your device by running fastboot oem lock and then get back to fastboot and run fastboot oem rebootRUU (case-sensitive) and then issue fastboot flash zip firmware.zip and also run fastboot flash update firmware.zip and reboot to fastboot again
4) If you had to relock your device unlock it by getting your Unlock_code.bin from HTCdev and issue this command when you're in fastboot which is fastboot flash unlocktoken Unlock_code.bin
5) download Duir's TWRP recovery built for KitKat which is located here https://drive.google.com/folderview?...3M&usp=sharing
grab the openrecovery-twrp-22.214.171.124-zaracl.img and then flash that by issuing fastboot flash recovery openrecovery-twrp-126.96.36.199-zaracl.img
6) Boot up into recovery, and format Data middle button on the right and type in 'Yes' and then wipe everything (you might have to reboot back into recovery again and then wipe everything) The reason to format Data using that button is because of KitKat remapping the partitions
7) Grab the KitKat TWRP backup from here https://docs.google.com/file/d/0B8-7...c4X0xoQXc/edit
8) while that downloads make a pseudo backup, and then when thats finished mount your SDcard and open up the KitKat TWRP backup on windows and just overwrite all the files in zara_cl442/zara_cl442 and then reboot back into recovery again.
9) Restore the Backup you made and overwrote with the KitKat TWRP backup
10) go into fastboot and go back to Duir's drive located here https://drive.google.com/folderview?...3M&usp=sharing
and grab KK_stock_boot.img and then flash that by issuing fastboot flash boot KK_stock_boot.img in a command prompt
11) Reboot into the System and it should work