Hi juliac, and welcome to the forum
I'd like to try Linux, can I use both Windows 7 and Linux together on the same computer as different programs?
Yes it's possible to set up a "dual boot" system, where at boot time you're asked whether you'd like to boot into Linux or Windows.
I'd prefer to see what it's like and if I can work with it before uninstalling Windows.
You have 3 options here -
a) Run Linux from a LiveUSB (USB stick) .. this will obviously be slower than running it from a hard drive, but will give you a taste of Linux without making any changes to your system.
b) Install either Linux Mint or Ubuntu "inside" Windows (kind of as an application .. though really it's a virtual hard drive) using the WUBI/Mint4Win installer .. this would allow you to easily remove it from within the Windows control panel .. downsides are it's harder to fix if/when things go wrong.
c) Install something like Virtaulbox in Windows (free), then run Linux from a VM (virtual machine) inside Virtualbox .. benefits are you can try lots of different Linux distributions easily, and the VM's can boot really quickly .. downside is your system is effectively running Linux on top of Windows so the system has to be up to the job.
1. If I transfer to Linus is it compatible with System Mechanic (Iola) software?
NO .. Windows software will NOT run natively in Linux, but there's nearly always a free Linux alternative in your software manager. From what I've seen of system mechanic most of its features are not necessary in Linux such as defrag/registry errors (linux file systems do not need defragging, and there is no registry), clearing of unused files can be done with something like bleachbit wich will be available in your Linux software manager for single click installation.
2. Is it compatible with Zone Alarm?
NO .. but for a home setup (and if you're behind a NAT router) you will need neither Anti-Virus, Anti-Malware, or Firewall for Linux .. and don't let anyone tell you differently.
There are many reasons for Linux being a secure OS and not needing those .. REAL security including file permissions, external files coming in without execute privileges, separation of kernel and user space, etc. .. but the fact that all the software you install all comes from the same software repository (which is checked for malicious code) and is installed through your software manager is one of the easiest to understand.
Any other questions .. feel free to ask