LINUX
Price
The majority of Linux variants are available for free.
Ease of Use
Although the majority Linux variants have improved dramatically in ease of use, Windows is still much easier to use for new computer users.
Reliability
The majority of Linux variants and versions are notoriously reliable and can often run for months and years without needing to be rebooted.
Software
Linux has a large variety of available software programs and utilities.However, Windows has a much larger selection of available software.
Software cost
Many of the available software programs and utilities available on Linux are freeware and/or open source. Even such complex programs such as Gimp, OpenOffice, StarOffice, and wine are available for free or at a low cost.
Hardware
Linux companies and hardware manufacturers have made great advancements in hardware support for Linux and today Linux will support most hardware devices. However, many companies still do not offer drivers or support for their hardware in Linux.
Security
Linux is and has always been a very secure operating system. Although it still can be attacked when compared to Windows, it much more secure.
Open source
Many of the Linux variants and many Linux programs are open source and enable users to customize or modify the code however they wish to.
Support
Although it may be more difficult to find users familiar with all Linux variants, there are vast amounts of available online documentation and help, available books, and support available for Linux.
WINDOWS
Price
Microsoft Windows can cost a considerable amount per each licensed copy.
Ease of Use
Microsoft has made several advancements and changes that have made it a much easier to use operating system, and although arguably it may not be the easiest operating system, it is still Easier than Linux.
Reliability
Although Microsoft Windows has made great improvements in reliability over the last few versions of Windows, it still cannot match the reliability of Linux.
Software
Because of the large amount of Microsoft Windows users, there is a much larger selection of available software programs, utilities, and games for Windows.
Software cost
Although Windows does have software programs, utilities, and games for free, the majority of the software the costs can be considerable
Hardware
Because of the amount of Microsoft Windows users and the broader driver support, Windows has a much larger support for hardware devices and a good majority of hardware manufacturers will support their products in Microsoft Windows.
Security
Although Microsoft has made great improvements over the years with security on their operating system, their operating system continues to be the most vulnerable to viruses and other attacks.
Open source
Microsoft Windows is not open source and the majority of Windows programs are not open source.
Support
Microsoft Windows includes its own help section, has vast amount of available online documentation and help, as well as books on each of the versions of Windows.
My opinion Linux, my reasons being many. They are probably best described here http://www.whylinuxisbetter.net/
LINUX AND WINDOWS TOGETHER
You can install Ubuntu 8.04.1 using Wubi installer. You keep Windows as it is, Wubi http://wubi-installer.org/ only adds an extra option to boot into Ubuntu. Wubi does not require you to modify the partitions of your PC, or to use a different bootloader, and does not install special drivers.
Wubi keeps most of the files in one folder, and if you do not like it, you can simply uninstall it as any other application.
LUg.