Windows only: vSubst lets you assign drive letters to any local folder on your computer, letting you turn it into a virtual drive. It's a good way to organise files or simulate environments.
If you forgot to partition during a reformat but really like to separate your data from Windows with a standalone partition, vSubst will allow you to make any folder appear as though it's a dedicated drive. In addition to easier access, you can use vSubst to create a virtual CD drive. (Note: If you really want a proper partition rather than a virtual drive, Windows has had a built-in tool since Vista that makes it easy to repartition your hard drive; alternately, this guide details the process using the popular GParted live CD.)
Substituted drive letters are removed at Windows shutdown, unless you create a persistent substitution. To remove persistent substitutions, the assignment needs to be removed in vSubst, and then you must delete vSubst.exe from C:Windows. Users should not use defragment or scan the virtual drives while using the program. vSubst is free and available for Windows only.