Close other things when playing Minecraft/when opening Minecraft. They take up RAM.
also:
- Go into your Task Manager (That thingy you get when you press CNTRL+ALT+DELETE)
- Go to the tab labeled "Processes" (It's next to "Applications" on my screen
- Under the "CPU" area, it should say 00 a bunch. There's also a few numbers, like 06, 15, 47, or whatever. They keep changing. Right? Find one that has a high number (Between 5-100) and read what it does. (Image Name/Description)
- If it's something that you recognize, such as Google Chrome (chrome.exe sometimes) and you don't need it, right click it and select "End Process" or "End Process Tree". I'm not 100% sure what the difference is, but I think "Tree" refers to "Selected process, and all related processes". Meaning it'll close down more, rather than you having to End all processes with the same name manually.
- If there's still a high CPU usage that you can't find the reason for, click "Show processes from all users" at the bottom, and it might show a few more that might be causing extra CPU usage.
DO NOT, and I repeat,
DO NOT end anything you don't recognize. If you need to, use Google/Yahoo/Bing etc. and search what it is before ending it. Java = Minecraft often. Chrome.exe = Google Chrome. Skype = Skype (Duhh)
If you accidentally end something important, force-shut down your computer (Hold down the power button) and restart it.
Be warned: This is what I do. If something bad happens to your computer, I'm sorry but it's not my fault (well maybe a little bit, but I didn't force you to do it.) This could damage something, but so far I haven't damaged anything seriously.
Use at your own risk