Did malware kick me as my Mac's administrator?

[Bryan]

In the midst of a normal work session, my iMac shut down. On restart, the fan was running (and still is), and I am no longer recognized as Administrator for my computer. I can still work on the Mac, and can go online, but operation has been slowed. Without Administrator status, I can't use any utilities to conduct repairs or scan for/remove malware. I've reinstalled a clean OS (Leopard).

I am the only user on this Mac. Changing the password in the installation disk utilities has not worked.

I suspect I've somehow imported malware. Is there any way for me to regain Admin status? I'm a self-employed work-from-home guy, and need my Mac like i need to breathe. I would greatly appreciate any advice/guidance.

Also, is there a way to turn off the computer fan?

Thanks in advance,
Bryan

 

[Bryan]

Fan problem solved. Unplugged the power cord at the back of the iMac, counted to 10, plugged back in ... and the fan was switched off with the restart. Weird.

But still can't solve the Administrator problem. Would greatly appreciate help with that.