You say the GPU temp goes up to 99°....it shouldn't if your just in the windows desktop, i.e not running a game. This is the point of MSI's 'zero Frozr' technology.
Use the software below to uninstall all traces of your driver package, then reboot your PC and confirm that the default windows driver is picked up on the card in device manager (try the AMD uninstaller first and if you get the same issue then uninstall via the DDU uninstaller on guru3d):
http://support.amd.com/en-us/kb-articles/Pages/AMD-Clean-Uninstall-Utility.aspx
http://www.guru3d.com/files-details/display-driver-uninstaller-download.html
Once your back in windows and have confirmed that the default MS device driver is driving the card, try to 'automatically detect and install your driver' from the link below:
http://support.amd.com/en-us/download