I'm back to looking at my 08 macbook. It runs slow, stalls and leaves me hanging aggrevatedly when using firefox to browse. it especially seems to dislike using gmail and youtube. It will have the busy wheel, and often just fail to respond. It's getting worse over time, by not letting me type for like 3 minutes long of the Wheel. My photos seem to also extremely aggrevate it. first i couldnt use the photos, then preview. then gmail started crashing the browser. then use of youtube and/or gmail. now even gmail in text version stalls the whole system keeping that busy wheel turning. So I got the idea to try some tests. I tried running Mac OSX Console app and looking thru the log for errors. There was plenty of stuff but I don't know what I'm reading. I am sure it has errors. Then I used Disk Utility app to verify disk. It said my disk was OK. Then the link a friend gave me http://www.chriswrites.com/2012/02/how-to-health-check-your-macs-hard-disk/ linked to a NovaBench diagnostics test. I DL and ran it. It went smoothly until after completing the 'Hard Drive Speed' test where it freezes and fails to continue with testing. My only option there is to cancel. Rerunning the test provides the same output/result. It has small lag with RAM/mem but it seemed to go thru that fairly quickly enough and it did complete the entire testing. Does this seem like it might be the HD? Will simply replacing my current (original) HD with an Upgrade to the HD to 500GB Seagate Momentus XT Hybrid HD help with my mac problems. (Where running gmail interferes with entire system operation and also the youtube but especially any of that combination together). Are there any more test you can recommend me to try? I am an absolute newbie but I know there is something wrong with my macbooks function. I love my macbook and would love to figure out whats up and then how to fix it. Its a durable reliable computer. Thank you in advance for any help you can offer. I also had recently reinstalled the entire OS with original disks, and it took like an entire day to load it all up. the first time i did this and got firefox on it, the whole thing crashed. this second time it's been working since july, although perfomance is just getting competely impossible now. please help. i dont really know what i'm doing, but i'm tech minded, can follow directions, and learn so i hope to have some feedback and get to work on it. thank you..