Do you have an asus ?
You should include board name in post,so now i have to hope you"d
have an asus.
If its asus,install asus probe from the asus cd or download it,
It's only for asus boards,so check any others for testing software.
Use 3rd party as a last resort.
But these readings are in the bios,Hardware Monitor.
But i know of no GPU temp reader.