I have been dual booting Windows + Linux for a long time but that has been a pain. Since Windows is my primary environment, I am unable to work on my Windows apps every-time I boot into Linux. I require both Windows and Linux to be available to me side-by-side so that I can conveniently experiment with Linux whenever I want to. In this article, we will find out how to easily run multiple Operating Systems at the same time, in a single machine.

• A decent computer with at least 1GB RAM (more recommended)
• VMware Player software
• Your favorite Unix/Linux CD or iso file; for me, I will use Ubuntu version 9.10 but this article works for any OS, any version

1. Visit the VMware Player download page
2. Click on Download
   
    
3. At the time of this article, the latest version of VMware Player is 3.0 => click on VMware Player 3.0 at the very bottom of that page to continue. If you happen to see a newer version, simply download the new version.
   
    
4. Locate “VMware Player for 32-bit and 64-bit Windows” then click on Download.
    
5. VMware would then prompt you to signup “Register for your FREE Download” on the top right. You need to register for an account in order to download. VMware will send you an email with an activation link. Note: it may take several hours for VMware to send out the email. For my case, it took around 20 hours
    
6. Once you have your VMware Player downloaded, simply double click on it and install.
    

How to download Unix/Linux:
In this article, I will use Ubuntu 9.10. Ubuntu is a very popular, stable, secure and very easy to use Linux Operating System. It is based on Debian and is ranked the top OS of all Unix/Linux OSs.

1. To download, visit ubuntu.com and click on Download Ubuntu
    
2. Under Download location, select your location (country) then click on the big green Begin Download button to begin your download.
   
    

1. Start VMware Player: Start => All Programs => VMware => VMware Player
    
2. Click on Create A New Virtual Machine
   
    
3. Selecting your media: If you have your Unix OS in a CD => select Installer Disk
   If you have your Unix OS in an iso file => select Installer disk image file iso
   For this article, I will use Ubuntu 9.10 ISO file.
   
    
4. Click Next then enter your login information. This is the login you will use to login to your Linux OS.
   
    
5. Click Next then enter your Virtual Machine name. I recommend entering it as “Ubuntu 9.10″ or the name of your Linux OS so that you can easily recognize the OS at a later time.
   
    
6. Click Next then enter your Disk Capacity. This is the maximum hard drive capacity limit you set for Ubuntu. I recommend 10Gig of disk space or more.
   
    
7. Press Next then press Finish to begin the Ubuntu installation. Once the installation is finished, to start Ubuntu, simply double click on Ubuntu 9.10 under Home
   
    
   
    

Here are some very useful Yum commands:

1. yum check-update
   This allows you to check to see if there is any update available for your installed packages.
    
2. yum update
   This will update all packages to the latest version.
    
3. yum update <package name>
   Use this to just update one package at a time.
    
4. yum search <keyword>
   You can use this command to search for any packages containing specific keyword. Pretty useful to locate the full name of a particular package.
    
5. yum install <package name>
   This allows you to install the latest version of a package. Yum will automatically install all dependencies.
    
6. yum remove <package name>
   Used to delete/remove a package, along with its dependencies if any.
    
7. yum localinstall <absolute path to package>
   With “yum install”, yum automatically downloads the package for you.  In case you already downloaded the package yourself, you  can use this command to install it. Make sure to state the full path to the package you downloaded.  i.e. yum localinstall /home/test.tar.gz
    
8. yum info <package name>
   Lists information about a package.
    

If you know more, please add to the list!

Via command line, type this:

cat /etc/redhat-release

To safely upgrade CentOS to the latest version, type this:

yum update

To install KDE Desktop, type this:

yum groupinstall "X Window System" "KDE (K Desktop Environment)"

To install Gnome Desktop, type this:

yum groupinstall "X Window System" "GNOME Desktop Environment"

After the installation is finished, type this to start KDE or GNOME:

startx