“Where do you get it and how would you go about replacing MS 7?”
I would recommend Linux Mint version 16, because version 17 just came out and will undoubtedly need some time for a few bugs to be ironed out. That is pretty typical of new software releases. You can always install the newer version later when it matures.
1) Specifically, I would recommend Linux Mint 16 “Petra” - MATE (32-bit). Here is a link where you can download a Linux image file: http://www.linuxmint.com/edition.php?id=145
2) After you have downloaded the Linux .ISO image file to your Windows PC, then you will need create a bootable Linux disk on a DVD from that image. This assumes that you have a DVD burner and related burning software already installed on your Windows PC. I think most disk burning software nowadays is able to create a bootable disk from an .ISO image file.
3) Shut down your Windows PC and reboot it from the DVD that you created. You will be able to “test drive” Linux without actually installing it. Later, if you decide that you want to create a permanent installation of Linux, you will be able to do by clicking an icon on the Linux desktop. I have not tried installing Linux side-by-side with Windows 7 and won’t guarantee that you could do that. I always tell the Linux installation program to overwrite the whole disk. Good-bye, Windows!
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