If you're nervous about the switch consider dual-booting. Then you're not fully committed to the switch & you can have your old Windows system back whenever you want it.

Main steps are:

• Run a defrag on your Windows machine to physically consolidate all your Windows data to one area.
• Break that partition into two (Linux will go one the new empty side)
• Install Linux from a USB as normal, but don't choose to wipe your drive completely. Choose a manual option instead where you specifically indicate your intended Linux partition from above.
• Optional: Once installation is complete you can set up another partition to hold files which can be available to both OSs.
  • Boot into Linux & define the remaining unused space in the Linux partition as a new NTFS partition & give it a name which makes it obvious what it is (i.e. "sharedspace")
  • Then boot into Windows and move the existing data you'd like to share between OSs here (work documents, movies, music, etc.)

Some useful links:

• Video on setting up a dual boot
• Howtogeek used to have a great walkthrough for doing this but I'm getting a 404 error when I try to follow the link now :(
• Optional: Setting up Linux symlinks to point to the shared space partition