I just got a macbook air - 13 inches.
1.Is it OK to leave the adaptor connected all the time? I mean, when it becomes green, it doesn't over charge the battery, correct? of course I will let the battery get to 0% sometimes.
It can't overcharge. Run on battery whenever you need to and plug it in whenever you can. You can plug or unplug at any time, regardless of the charged percentage. Just make sure you don't run on AC power all the time, as your battery needs to be used regularly to stay healthy.
2.DO I need any kind of antivirus?
Macs are not immune to malware, but no true viruses exist in the wild that can run on Mac OS X, and there never have been any since it was released over 10 years ago. The only malware in the wild that can affect Mac OS X is a handful of trojans, which can be easily avoided by practicing safe computing (see below). Also, Mac OS X Snow Leopard and Lion have
anti-malware protection built in, further reducing the need for 3rd party antivirus apps.
- Make sure your built-in Mac firewall is enabled in System Preferences > Security > Firewall
- Uncheck "Open "safe" files after downloading" in Safari > Preferences > General
- Disable Java in your browser (Safari, Chrome, Firefox). This will protect you from malware that exploits Java in your browser, including the recent Flashback trojan. Leave Java disabled until you visit a trusted site that requires it, then re-enable only for the duration of your visit to that site. (This is not to be confused with JavaScript, which you should leave enabled.)
- Change your DNS servers to OpenDNS servers by reading this.
- Be careful to only install software from trusted, reputable sites. Never install pirated software. If you're not sure about an app, ask in this forum before installing.
- Never let someone else have access to install anything on your Mac.
- Don't open files that you receive from unknown or untrusted sources.
- For added security, make sure all network, email, financial and other important passwords are long and complex, including upper and lower case letters, numbers and special characters.
- Always keep your Mac and application software updated. Use Software Update for your Mac software. For other software, it's safer to get updates from the developer's site or from the menu item "Check for updates", rather than installing from any notification window that pops up while you're surfing the web.
That's all you need to do to keep your Mac completely free of any Mac OS X malware that has ever been released into the wild. While you may elect to use it, 3rd party antivirus software is not required to keep your Mac malware-free.
If you still want to run antivirus for some reason,
ClamXav (which is free) is one of the best choices, since it isn't a resource hog, detects both Mac and Windows malware and doesn't run with elevated privileges. You can run scans when you choose, rather than leaving it running all the time, slowing your system. ClamXav has a Sentry feature which, if enabled, will use significant system resources to constantly scan. Disable the Sentry feature. You don't need it. Also, when you first install ClamXav, as with many antivirus apps, it may perform an initial full system scan, which will consume resources. Once the initial scan is complete, periodic on-demand scans will have much lower demands on resources.
3.Is it possible to put some soft sheet between the keyboard and the screen when I put it in my bag so the screen won't get scratched?
Yes.
4.I have applied for the free Mountain Lion upgrade but I still didn't get a confirmation Email from Apple.How much time will it take?
Up to date validation-- How long?
5.Is it normal that when I have a fully charge battery and the screen brightness is almost at maximum, it says i can only have 5:00 hours to use the computer? it says 7 hours in their website...
From the BATTERY LIFE FROM A CHARGE section of the following link:
- Your "time remaining" indication is an ever-changing estimate, based on the current workload of your system. It will fluctuate up and down from minute to minute as your power demands change. It is not perfectly accurate, but only an estimate.
There are many factors that impact your battery life. See the BATTERY LIFE FROM A CHARGE section of the following link for details, including tips on how to maximize your battery life.
This should answer most, if not all, of your battery/charging questions:
