There's no "latest version" of Coolbits. It's just a registry hack, not a program. Copy/paste the following into a text file with Notepad:
REGEDIT4
[HKEY_LOCAL_MACHINE\SOFTWARE\NVIDIA Corporation\Global\NVTweak]
"CoolBits"=dword:00000003
Name it "coolbits.reg" and double-click to install. That's it.