You got a .rar file and you don't how to open it, some one asked you to send him "a rar file" or you just need a good archiving software? Download and install WinRAR.
If you are a heavy twitter use, possibly with more then one account, than I suggest you to give Tweetdeck a try. You can arrange, schedule, monitor and manage your tweets with ease.
It's highly recommended to protect your computer against Virus, Malware, Spyware and other potential threats. Microsoft Security Essentials is one of the better, free solutions.
Power Search was a real useful feature and there is now good reason why Apple decided to ditch/hide in iTunes version 11. But luckily you can bring it back quite easily. Check it out.
We will install VLC player, which is one of the most versatile players. The biggest advantage of the VLC player is that it does not need any additional codecs.