You're very welcome.
Sorry that updating the IMEI driver didn't work.
The only other suggestion I can offer to rule out a software issue, would be to disconnect the power or data cable from the hard drive, turn the PC on and then switch it off. With no OS involved, that rules out a software problem.
If the fan still goes crazy, then your PC most likely has a hardware issue.
If it doesn't, then I would suggest you do a clean install of Windows 7.
If it is a hardware issue...exactly what component might be the culprit...that I do not know.
I do know that if your luck is anything like mine, whatever component you decide to replace first (motherboard or power supply), it won't be the right one. 