abylon CRYPTDRIVE is a decent app, but I can't find a reason to suggest using it rather than the open source VeraCrypt [veracrypt[.]fr]. Both can do the same thing, create and mount an encrypted VHD [Virtual Hard Disk] that appears in File Explorer like any other drive partition, USB stick etc. Compared to having however many files in a folder compressed into an encrypted 7-Zip file, the end result would effectively be the same, though with the VHD you won't have to worry about deleting or shredding the unencrypted files on your hard disk after (re)encrypting them. Depending on the number & size of the files, opening [mounting] the encrypted VHD could also be faster than expanding a 7-Zip archive. You can also do things like install & run app's from an encrypted VHD -- really anything that you would do with a regular hard disk / SSD. VeraCrypt can also work as an alternative to BitLocker, encrypting the entire hard disk with Windows installed, has the option to hide a nested encrypted VHD inside an encrypted VHD -- you can open the outer VHD to show whomever the contents without revealing the existence of the hidden VHD -- and VeraCrypt can work portably, though you will get a couple few registry entries & it does by necessity use a driver. That said, for biz use abylon CRYPTDRIVE might be a bit friendlier, since like BitLocker it has an option to let the boss access its encrypted VHDs.
Neither abylon CRYPTDRIVE or VeraCrypt is difficult to use, but then neither one is really user friendly either -- you'll have to do a little reading & pay attention to what you're seeing on screen. abylon CRYPTDRIVE also adds it's own driver, along with Microsoft C/C++ runtimes, and requires restarting Windows. VeraCrypt has 3 download options, an MSI [Windows] installer, a regular installer that also lets you just extract the files for portable use -- the MSI installer may offer that option also, but I didn't try it, and a portable version in a self-extracting file. I don't know why they have more than one portable option, and there's more: you can encrypt an entire external drive / USB stick, same as a hard disk partition, and you can create what they call a Traveler disk / USB stick, which has the portable version on it but Not the encrypted VHD, which is basically the same thing as the portable version on a USB stick that you haven't added any VHDs to [yet]. And as if this wasn't already complicated enough, you can always create Windows own .vhd format VHDs in Windows, which will even boot to them, and those can be encrypted however you want as well. One thing to note overall, as the VeraCrypt docs point out, if the storage uses wear leveling &/or Trim [e.g., most SSDs], it might be possible for someone with the right tech equipment & know-how to read some unencrypted data [though this is more in the realm of university researchers and spy agencies IMHO].
Installing abylon CRYPTDRIVE adds the app's folder; the C/C++ runtimes with their own package cache folders, installer folders, almost 2 dozen files in Windows\ System32\, and loads of registry entries; a driver: C:\Windows\ System32\ drivers\ apmdrive.sys; C:\Windows\ System32\ config\ systemprofile\ apm\ abylonsoft\; C:\Windows\ SAPReg.ini; an abylonsoft folder in [My] Documents; a LOGS folder & an abylonsoft folder to Public Documents; an APM folder to ProgramData. I recorded ~700 new registry entries in my Win7 32-bit VM.