Hello. I really hope someone can give me some advice on what I should do with my newly serviced IMAC. I have had the MAC since 2006 and had no issues with it. The computer had OSX Tiger on it and I was very happy with it. The MAC is an Intel based MAC with 1GB of RAM, 160GB HD, Leopard 10.5.5. About a Month ago my hard drive crashed. Could not recover it, or fix it. Had my applecare warranty still intact so went ahead and took the computer in. Genius folks checked it out and said they would need to replace the HD. No problems as I had backed up my data using Superduper. Got my computer back and behold....it has Leopard installed on it with all my data recovered. I was surprised and also a bit excited to have the new OSX. As I begun to use the system as regularly i did, I noticed 2 significant changes over the computer I originally took in. 1. System was running signficantly slower. Almost seeing 10 seconds of hang for opening applications and approx 30 seconds of hang at times during application use. 2. Hard drive makes a lot of noise during write process (which is going on all the time). During even internet browsing, the hard drive is constantly writing. Noise is loud enough to hear it even a few feet away from the computer. What I wanted to find out from the folks on this forum is what your thoughts are? Should I take it back to Apple and ask them to put my Tiger OSX back on? (already called the store and they said it is not regular operating procedure to upgrade the OS. May have been needed or a mistake. When I asked for new start up disc's they said I had to buy the OS. I was a bit annoyed by this response as I did not ask for the upgrade). Or is my issue more the new hard drive and should i take it back to apple for the noise and slowness due to this? I thank you in advance for your help on this. Please let me know if there are any specifics to my case that may help in your advice. I'll provide the details as soon as I can get them.