noisy hard drive after installing lion

Thank you for that info. How does one schedule this? Is this done by calling the Apple store or calling Apple care?

Contact AppleCare.

Follow these instructions, make a option bootable Snow clone and try Lion again. If Lion doesn't work again, then the Snow clone is just a option boot, drive erase and reverse clone away.

How can I uninstall OS X Lion and go back to Snow Leopard?

1: Copy your user file folders (Documents, Pictures, Movies, Music, not Library) to a external blank Disk Utility formatted HFS drive (not TimeMachine) and disconnect all drives. Make a note of your username and hard drive name. Write down any essential information like passwords stored in keychains and product serial keys.

2: Stick the 10.6 installer disk into the machine and reboot holding the c key down. Second screen in choose Disk Utility from the Utilities menu.

3: On the left select the hard drive makers name of your internal boot drive (important) then click Erase and Erase... button (if you want to wipe the drive of all lingering data then choose Security Option>Zero all data) when choosing a name for the drive, use the same drive name as before.

4: Quit and install 10.6, then go through setup, reboot and use the same user name as before. Software Update, install programs from fresh sources (enter any serial keys) Hold Option and click on Purchases in AppStore to redownload (not Lion of course) and then finally return user files to their respective folders on the Snow Leopard drive.

5: If you have issues with iPhoto, you can right click on the iPhoto Library and "Show Package contents" and in there is a folder with all your originals. Copy them out and delete the iPhoto Library and reboot, restart iPhoto and it should be recreated, which you can then import your copied originals again.

Note: using the same drive and user name as before, returning files exactly into their respective Music, Documents and Pictures folders like before matches any pathnames some files like iTunes has to the location of your files. If not done, then exclamation points will occur in iTunes when you click on a song. The iTunes Library will have to be opened in Text Edit and all the partial pathnames "find and replace" corrected to repair.

Optional, but recommended.

Ideally it's best to first Carbon Copy Cloner the 10.7 internal to another blank external HFS drive before doing the above steps 1-5 as that way you have a copy of everything in case you missed something or you need to hold option boot from the 10.7 clone. The clone can later be erased and used as a 10.6 clone. Or reversed cloned back onto the internal drive or as many external drives as needed. (don't use a clone on a different Mac)

Clones are hold option key bootable, TimeMachines drives are not.

Note: The above steps are ONLY for Mac's that didn't come with Lion preinstalled. For reverting a factory Lion to Snow Leopard requires other methods.

I also am experiencing what everyone else is saying. Biggest complaint is the constant hard drive grumbling and the slow wake from sleep and going back to sleep before the login screen appears. Like everyone else, it was fine with snow leopard. Hopefully we will all get some relief with an update soon!! Apple are you listening to us??I have a 2009 iMac with 4gb memory and 1tb harddrive.

Same problem here with a 5 months old iMac 27", 1 tb. After a Lion update the noise appeared and just won't stop. Ever. Why is there no one from apple support who can shed light on this apparently not so rare phenomenon???

What do people do - get a new one or is there some software to fix the problem? I AM GOING DEF...

Ditto to the constant hdd noise / activity. Refurb 27" iMac 1 TB hdd. Even idling w/ no apps running, the hdd is almost constantly clunking away. Has anyone here found a solution?

Update: Now my iMac stopped making the noise but it is only because it shut down and now it won't start again. Hope my HD isn't crashed:(

Apple products simply aren't what they used to be...