Yes, Recover My Files will get all your files back.
From your post it sounds like you now have an external drive which does not have a partition?
Do NOT format the drive as this can make data recovery more difficult.
Download Recover My Files (
http://download.getdata.com/RecoverMyFiles-Setup.exe) and install it and run it on your C: drive.
First try running a "Fast Format Recover", and in the drive selection window, look for the "physical" drive (i.e. the physical hard drive connected to your PC - you should be able to tell which one it is by the listed size). At the end of the search (which should be less than 1 hour) look in Folder View of the results screen for yoru files and click on them to preview their content in the preview window of the results screen. If you can see them, then you can activate the software and save them to your C: drive.
If a Fast Format Recover does not work, next try a "Complete Format Recover". Search the physical drive and search ONLY for the default selected file types. At the end of the search Recover My Files will rebuild the entire partition and display the results in Folder View of the results screen.
Best of luck.