go to htc-dev and unlock your bootloader -
http://www.htcdev.com/bootloader/
re-flash TWRP recovery (2.6.3.3) - fastboot flash recovery TWRP.img
and re-flash a rom (if you don't have a rom on your sdcard you'll need to push or sideload a rom to your phones SDcard
the command is adb push name of rom.zip /data/media/0 change the name of course
here is the Nandroid Backup CID BM 001 3.23.666.1 for your phone
http://www.htc1guru.com/dld/m7-twrp-nandroid-backup-cid-bm___001-3-23-666-1-zip/
You will extract the Backup to your fastboot folder (make a folder called backup in fastboot) and then push it to your phone while it's booted to Recovery
adb push backup /data/media/0/TWRP/BACKUPS/Your phones Serial number/backup
you get your phones serial number by typing adb devices