Installing Windows 10 - Upgrade vs Clean Install

I have 5 systems I am planning to upgrade to Windows 10, they are Windows 7 and 8 based systems.

I have a few questions about doing a clean install vs an upgrade install.

First of all, is it even possible to do a clean install with that free Win10 offer? Is there any way you can boot into the Win10 installer, then it can check if you already have 7 or 8 installed, then allow you to format the drive and install fresh? I prefer clean installs to upgrade installs in most cases.

One of the systems however due to many apps and settings I have configured on it, I would prefer to do an upgrade install, and I have some questions about that too. First of all, this may be incorrect information, but I was told that it only keeps some of your settings such as your drivers if you choose NOT to keep personal information. That doesn't sound right... So anyway, what does and doesn't it keep? I wanted to do an upgrade install for this system because of all the settings I wanted to keep, will all my apps still be there?

Speaking of which, this system also runs off a SSD, so space is a concern. How large is the Windows.old folder it creates? Can you remove it? I am planning to image the drive before I upgrade to 10 so I can always image it back to 7 anyway, I don't need a downgrade option.

And finally, speaking of drivers. I have a VERY old printer that I do NOT want to replace, by some miracle, the XP64 drivers (the latest OS it had drivers written for) work fine in Vista and 7, they gave me no trouble. (Not sure about 8 as I never installed that printer on a 8 system) but when I tried it on a Win10 system, it complained that the drivers weren't signed. I have run into this annoying signed drivers issue before, but if neither Vita64 or 7 64 complained about them, why would 10? Would it refuse to use my printer if I do an upgrade install to 10?

I did an upgrade over Win 8.1 Pro. My programs, AFAIK, are fine. I also didn't want to reinstall my stuff.
As for your printer, time to shoot that thing, or bite the bullet.

Since the early days of in place Windows upgrades I've always had problems. I've never found upgrade installations to work right. A clean installation is always the best option despite the additional time it takes to get your applications loaded.

I concur with Dan, but on a lark I updated a G750JH laptop and a x79 desktop build with nary an issue. This marks the 1st time I've done a Windows upgrade and not done a clean install after within 72 hours. However, that doesn't mean I didn't image both machines' disks just in case .

To your first question, no you cannot do a clean install of windows 10 while you are running 7 or 8/8.1. You must first upgrade to 10, and then you can do a clean install. That's how Microsoft knows you are legit. Otherwise you could just clone any drive with 7 higher on it, throw it in a machine and boot to the windows 10 installer. See the hole there? You have to be booted into windows with it activated and upgrade to 10.

I have done several upgrades, all from windows 7. In every case, all of my applications have been brought along just fine. It does a scan before the upgrade and will notify you if you have any incompatible apps or hardware, so you'll know what to expect before it is done.

About your final question, I'm thinking your printer won't work but that's just a guess. As I just mentioned, w10 will scan your system and most likely tell you that your are SOL on the printer.

I don't get the hype about clean installs vs upgrades, to be honest. I'd MUCH rather do an upgrade and not have to reinstall all of my games and apps... it saves me literally days of work. And in the end I don't believe there is any stability or performance difference.