The rom and development community always comes through with updates for old and end of lifed devices far after the OEMs have forgotten about them. The HTC Desire C was released way back in 2012. The last official update for the device was froyo! Now you can run Lollipop on the device thanks to developer "h1gh1". This is an unofficial build, but should be usable as a daily driver. The only parts of this rom that are not working are the camera, bluetooth, and video decoding and encoding. You will need to be bootloader unlocked with TWRP installed. Also be sure to install the latest version of TWRP 2.8.5.0 since it has actually been updated to handle Lollipop's file system. Head to the link below for the download.
via XDA