If you want an alternative to Windows operating system, you can try PC-BSD. It is a unix-like OS and is compatible with some linux software.
Why would you want to try this? Well, if you have an old computer that does not have the RAM to run the newer versions of Windows or if you have assembled a computer and don't want to pay for Windows 7 or Windows 8, this is an OS you can try. It is easy to install and it is free. I am not sure how useful it will be if you have printers and scanners that are Windows compatible but I am told that if you want to surf the web, email, listen to and organise music and store and edit photographs, this OS can do it.
While I haven't tried this OS extensively, I did manage it install it into my computer that had Vista originally but which became corrupted after time. A reinstall of Vista did not work and I decided to try this OS. I share my experience with you here.
Since Vista was not working on the old computer, I worked on my netbook to get the installation and other necessary files.
You begin by downloading the software from http://www.pcbsd.org/en/download.html.The page confused me at first because the download button at the top right of the screen led nowhere. Scroll down and on the left hand side will be a list of software to select from.
I selected the USB version as the DVD drive on the old computer was not working. This meant that I would be installing the OS from a thumbdrive plugged into a usb port. The file I downloaded was PCBSD9.0-x86-USBFULL.img.bz2 This is a zipped file. I unzipped it using Peazip (http://peazip.sourceforge.net/). The extracted file was a .img file a little over 3 GB.
I copied the extracted .img file to a newly reformatted 4 GB thumbdrive and tried an installation but it did not work.
I consulted the pc-bsd wiki http://wiki.pcbsd.org/index.php/PC-BSD_Users_Handbook and realised that the .img file had to be written to the usb thumbdrive using a program like Win32DiskImager. This I downloaded from http://www.softpedia.com/get/CD-DVD-Tools/Data-CD-DVD-Burning/Win32-Disk-Imager.shtml
The download was a zipped file and had to be unzipped. Using Win32DiskImager to write to the thumbdrive was easy. However to check if the file was written was difficult because I kept getting a zero byte reading. It seemed as if nothing had been written to the thumbdrive. Despite being unable to see what was on the thumbdrive, I was certain that the file had been written since Win32DiskImager did not report any errors.
I then changed the computer setup to make the usb drive the boot drive, put the thumbdrive in the usb port and restarted the computer. After lots file checks and status reports, the installation page finally came up.
The interface was graphic so there was no commands to enter.
So now I have PC-BSD installed.