I am having a problem with running Snow Leopard on my MBP. It's running extremely slow and beachballing a lot. Here is the issue. The computer is almost 3 years old to the day and is a Core 2 Duo MBP and has 4GB of memory. I upgraded to Snow Leopard a few months ago and am running the newest update. About 6 months ago I experienced a video problem and the Apple Store replaced it with a new logic board. A few days later I experienced networking issues. it would connect to Wi-Fi but would not get any internet. The Apple store tried a few things to fix corrupt files and was unable to fix it. They suggested a reinstall of Leopard which is what I was running at that time but instead I did an upgrade to Snow Leopard. It immediately fixed the problem and my computer was running fast. I left this out but as part of the Snow Leopard upgrade I upgraded the hard drive to a 640GB drive. Then a few days ago it began running slow. It seems to start slow so I thought it was just too many programs running and my computer was showing it's age. Yet it has gotten far worse and I know it may be a deeper issue. I have questioned if it could be an issue with memory. Would this slow it down? I tend to think its' software related, not hardware. The question: How do I troubleshoot something like this? It happens as soon as I boot it up, I don't even have to start any programs. I have looked at my login items in accounts and see a few things like growl and a scanner application. The only other thing I see is I noticed there is 4 items relating to SOHO Organizer. I don't believe these should be slowing it down. As an example when I boot it and log on at that point, it can beachball for 10 minutes before I get into the screen with the dock, etc. Dashboard won't even work. When I click on dashboard it brings up the calculator, weather, etc. but nothing opens up. i simply see the blank calculator but nothing is lighting up to type on it, no weather details, etc. and this is after bootup or using it. When I try to close an application it can take a minute, it can take a minute to switch, it. My computer is nearly unusable. If necessary I'll go to the Apple store but it just left the warranty period and I'm convinced its' simply something software related, maybe something that's hanging it. Any ideas of what could be wrong or how to troubleshoot to find out? Thank you in advance for your help.