I just wanted to come back in here and clarify my answers to "pinellascomputers", as I feel my original response was not very comprehensive. I will address their points one at a time.
Why your arguments for Windows 7 are invalid:it is built on Windows XP/NT core structure
So is Windows XP, so this is NOT an advantage.
It has built in problem solving
This is extremely vague, and doesn't have any specific meaning that can be addressed.
[it has built in] hardware installation
This has been a feature of every version of Windows (and all other OS'es) since the 1990's, so this is NOT an advantage.
[it has built in] 3rd party driver detection and installation
This has been a feature of every version of Windows (and all other OS'es) since the 1990's, so this is NOT an advantage.
It has multi level security features
Again, very vague, but all Windows versions after Windows 95 have had multiple levels of security control, so this is NOT an advantage.
[it has] one of the best file sharing systems
File sharing is extremely simple on ANY operating system, so this is NOT an advantage.
[it] creates automatic and customized backups
Most users will never use this tool, but if they wanted to, there are excellent free and easy methods to do so that do not rely on one particular format or manufacturer.
it informs you of problems it encountered
Both Windows XP and Linux do this as well, so this is NOT an advantage.
it searches your entire computer from the start menu
Both Windows XP and Linux do this as well, so this is NOT an advantage.
it has aero window previews, taskbar jumplists, snap...
Most users do not know about, care about or use these features, but Windows XP and Linux have very similar features that can be added or turned on should anyone want them, so this is NOT an advantage.
it detects and identifies every device, and can even figure out what to do with unknown hardware
This has been a feature of every version of Windows (and all other OS'es) since the 1990's, so this is NOT an advantage.
you can run it in compatibility mode for XP or early versions of Windows
This is only needed if you use Windows 7, but XP has backwards compatibility as well. Free alternatives to most popular applications are widely available for XP and Linux, so this is NOT an advantage.
Why your arguments against Linux are invalid:[re: Linux] don't count on 95% users knowing how to mount drives, and sudo software installations
Most users will never attempt these types of operations on ANY operating system, so this is NOT a disadvantage.
[re: Linux] not being able to use a large number of Windows/Mac programs that aren't currently supported [by Linux]
The vast majority of users rely on programs that have completely free equivalents for Linux, so this is NOT a disadvantage.
I would love to debate this topic further.
I'm happy to debate it with you as well, but we'll do it here, in public where everyone can see. Feel free to respond here in the thread I have created for this purpose.
Now, I could be wrong, but I strongly suspect that "pinellascomputers" makes good money installing and troubleshooting Windows 7 for his clients. The facts that all of their arguments are so hollow, and that they have refused to respond here so far, reinforces my belief that their motivations are in their own best interests more than their customers'.