Hello! Yesterday, I was using my MBP and it was running perfectly fine, not slow at all, everything opening fine. A bit later, my friend wanted me to play Counter Strike, which runs only on Windows. I restarted my computer and ran Windows 7 using Boot Camp. While I was playing the game, I noticed that my mouse would sometimes freeze up for a second or so. I shrugged this off. After we finished gaming, I restarted again and ran Mac OS X Lion instead. WOW! What a change! I have 4GB of RAM on this MacBook Pro, and in the Activity Monitor, it would show that I have < 50 MB free, even though I have like 2 programs open. TextEdit would constantly freeze and I would have to Force Quit the program. I would constantly get the spinning rainbow wheel when doing something on Safari. Opening a new tab would take 30 seconds. The system overall is running very, very poorly. What happened? 2 hours ago, before I restarted and ran Windows 7, it was running perfectly smooth. Now 2 hours later, it is running atrociously! The MBP is a 2011 MacBook Pro 13": Intel i5, 4GB of RAM, stock 320GB HDD. Any ideas? Thanks! Update: while I was typing this up, I was Repairing Disk Permissions using the Disk Utility - after it was done it made Available RAM to go from about 20 MB to 1.52 GB - so that's a good sign. However, I don't feel that the problem is solved yet.