The SMC Firmware Update 1.0 is a System Management Control (SMC) firmware update for certain Intel-based computers, including iMac (Early 2006) computers. Tip: Print or write down these instructions before you begin installing the update.
There are two parts to this process: Installing the firmware update application, and using the firmware update application to install the SMC Firmware Update.
Download the SMC Firmware Update 1.0, which is available at Apple Downloads. Quit open applications, which are marked in the Dock with a small triangle. Double click the SMC Update.pkg file. Click Continue after reading the licensing agreement, then click Agree if you accept the terms. Click Install to install the update application. After the software is successfully installed, click Close to start the updater application. (If you inadvertently skipped this part, you can find the updater in /Applications/Utilities.) Read the onscreen firmware update installation instructions, then click Restart to proceed. As your computer starts, the SMC will be updated. Your computer's fans will run at full speed during the update but will return to normal once the update completes. The computer will restart again once the firmware update is complete. Important: Do not interrupt the update process.
After your computer restarts a second time, you should see a message stating that the update was successful. Click OK to continue.
Note: If you see the dialog that you saw in step 7 instead of a message that the update was successful, try installing the update again (use the updater in /Applications/Utilities/).