In my experience, dual-booting on a PC between Windows and Linux can lead to various types of problems. Lack of Hard drive space for one and Windows having a nasty habit of re-configuring your system without your permission, can mess up your boot loader.
I once had the unpleasantness of Windows updating and failed to start. grub failed to boot and I was stuck at a command prompt. in the end I had to Use a Live cd, back up the data i wanted and re-formatted the hard Drive.
My suggestions involve a bit of work and you may need to spend some money but in the end, they are worth the time and trouble.
I'm going to assume that your PC is Desktop. if that is the case, acquire a second hard-drive and install it into the system. Then install Linux onto that 2nd hard drive. On installation Grub should recognize the second hard drive and set it up as when you were dual-booting before. If that doesn't happen, at boot time press the Function key that allows you to manually choose a boot device, and choose the hard drive you installed Linux on, to boot from.
The 2nd method require you using an external hard drive. You can buy the completed one, or buy a separate kit and hard drive. to be honest, it would be more advantageous to buy the external hard drive kit as you would be able to replace the hard drive, in case of failure as well use replace numerous hard drives with various data. This way you can travel with a Linux ready Operating System everywhere.
As far as Linux distros go, although Ubuntu and Linux Mint are the more popular, there have been a lot of problems with these two concerning ENIGMA. It not ENIGMA fault. trying to installing it always ends up with some error which affect ENIGMA. After various testings with a number of distros, I found two that ENIGMA installed flawlessly. These two are Trisquel and MX Linux.
Information on Trisquel can be found at http://www. trisquel.info
Information on MX Linux can be found at https://mxlinux.org
Hope this have helped you out even a little. Keep up the good work.