Deciding on using UNIX or windows should be a strategic decision for any firm who has at least one IT employee. It determines if you hire someone with UNIX administration skills or windows administration skills. While exceptions can be made it is best to try and stick to one or the other as much as possible unless your firm really is large enough to employ (and want to employ) both windows and UNIX administrators. You should also select the flavor of UNIX as a standard and only change as a strategic decision. (It is easier to support and maintain just one.) The decision should be made based on what is best for the business not a personal preference. There are pros and cons of both operating systems.
The number one reason that people select Windows over UNIX is that they know nothing about UNIX and cannot support or maintain it. Windows people administer windows boxes and UNIX people administer UNIX boxes. If you are not familiar with windows servers (even if your familiar with Windows desktops) then it really doesn't matter. Unix isn't as hard as most people think and you probably will have to call an outside contractor either way. Otherwise don't even think about running a server your firm cannot support. Unix (especially Linux) might be cheaper and windows might seem like an easier option. However if it cannot be maintained the business objectives will not be met and it will cost more than you can imagine. When it breaks the staff cannot fix it; and routine work suddenly becomes difficult.
The number one reason that people select Windows over UNIX is that they know nothing about UNIX and cannot support or maintain it. Windows people administer windows boxes and UNIX people administer UNIX boxes. If you are not familiar with windows servers (even if your familiar with Windows desktops) then it really doesn't matter. Unix isn't as hard as most people think and you probably will have to call an outside contractor either way. Otherwise don't even think about running a server your firm cannot support. Unix (especially Linux) might be cheaper and windows might seem like an easier option. However if it cannot be maintained the business objectives will not be met and it will cost more than you can imagine. When it breaks the staff cannot fix it; and routine work suddenly becomes difficult.