It sounds like the BIOS configuration for fan speed control somehow got corrupted and restoring defaults fixed this corruption. This kind of corruption, in addition to affecting fan control, can cause Intel(R) Desktop Utilities (IDU) to get into this mode where the spinner appears seemingly forever.
If you get into this situation - and restoring defaults (and/or reinstalling IDU) - leaves the spinner spinning, send me a message. Attach to this message the following file:
on 32-bit Windows installs: "C:\Program Files\Intel\FSC\FSCAppServ.log"
on 64-bit Windows installs: "C:\Program Files (x86)\Intel\FSC\FSCAppServ.log"
...Scott