I gave Windows 10 a chance. I was going to do multiple booting with Windows 10 and other systems. It has some interesting new application features, including stand-alone Web-based instances of several common Web-based applications, such as Mail, Facebook, Twitter, Amazon Kindle, and probably many others too.
This Dell Inspiron 15, Model 5558, has quite a bit of memory - 8 GB, the disk is a ST1000LM024_HN size: 1000.2GB - that's 1 Tera byte or 1000 GB. So this system has plenty of space, plenty of memory, and plenty of processor capability.
Windows 10 ran "OK", but that was about it. The system ought to run well. The problem is that it didn't, not in every respect. The networking must have been a work in progress, or perhaps a "rework". It had trouble remaining "up"; connections would regularly drop and reconnect.
So after a trial of several weeks, where I was booting from USB often, just to get a system that would keep the network "upright" (MX-15), I finally canned Windows 10 and sought to find some Linux systems that would work.
I had some unexpected difficulties. It took me a lot longer than I initially intended to get a good file system configuration and a boot loader that would work properly with it. I could have - and I did for a while, go to an old fashioned IDE disk configuration, with up to four primary partitions and a few extended partitions, but that is a misuse of this hardware. I then went to a "GUID Partition Table (GPT) is a standard for the layout of the partition table on a physical hard disk, using globally unique identifiers (GUID). Although it forms a part of the Unified Extensible Firmware Interface (UEFI) standard (Unified EFI Forum proposed replacement for the PC BIOS), it is also used on some BIOS systems because of the limitations of master boot record (MBR) partition tables, which use 32 bits for storing logical block addresses (LBA) and size information on a traditionally 512 byte disk sector." (quoted from https://en.wikipedia.org/wiki/GUID_Partition_Table ).
I now have several Linux-based systems installed: Fedora 23 (Xfce), MX-15 (Xfce), Debian 8.2 (Xfce), Linux Mint 17.3 (Xfce), antiX 15, and openSUSE Leap 42.1 (Xfce). All of them are 64-bit implementations, all of them are now bootable from the UEFI boot loader, which is implemented on Fedora 23 and openSUSE Leap from the GRUB-EFI implementation. I used Fedora 23 to get the multiple systems accessible, and I also have multiple USB sticks that I can alternatively use to access not only this, but other systems as well.
After over a month of fiddling around, I now have things in a pretty usable form and all of them readily outperform Windows 10, plus most of them have similar capabilities. I really don't need Windows any more. I use Google Docs and Libre Office for the occasional office application and I have no other home needs for anything else.