Not my Win 7!

It's ReactOS in a VM. Not HL2 playing in Windows in a VM on ReactOS. That would be nothing to talk about.

If you have spare hardware lying around, you can probably try it out and let us know.

Ah OK, that's something.
Not enough to make it interesting, but indeed much more interesting than what I thought it was.

It also looks like Windows Server 2003 or Server 2008. Or Windows XP, Vista or 7 with the Classic theme. I fail to see your point.

The point is, that it looks like Win 98.

Dunno, but I've been following the project since before it was called ReactOS in the mid 90s. It's an interesting academic curiousity for sure. I poke it with a stick to see if it's still alive about once a year or so just to satisfy personal curiousity, but that's about it. :)
Yes, is that just a neutral observation? I get the idea others think you mean something specific good or bad. :)

IMHO, it's one good thing ReactOS has got right. :) I'm not fond of all the UI changes Microsoft has made to "improve" Windows over the years. I can bear part of the default Windows 7 theme/UI defaults but I go around reconfiguring half or more of it to look like Windows XP or thereabouts, taking some of the new stuff that are actual improvements and reverting to the old where I find the old to be superior for my own purposes, whether technically or simply due to personal habit etc.

Ultimately it doesn't matter too much what it looks like though, that's all replaceable in theory and just cosmetic. What matters is what's under the hood and what apps will run on it, as well as what hardware it will run on and what hardware is compatible with it for gaming etc.

I'm not confident ReactOS will ever run enough games reliably though compared to what one can get running natively or via wine or KVM etc. inside Linux already though. It just doesn't have the same amount of developers contributing to it as Linux does and most likely never will. It's still an interesting curiousity though and it's nice to have options out there.

Funnily enough, so did Windows NT.

Yep, NT was a Win 98 vlone, with slghtly better networking abillities (Hm, not sure if I wrote abillities right!).
NT = Neandertal Technology :-D

Well, not really, no. Win 95, 98 and ME were essentially built on top of DOS. DOS was the kernel that powered it, and it was inherently insecure as a result. The NT operating systems on the other hand ran on top of the NT kernel, which allowed for differentiation between system space processes and user space processes (like Linux) and was (at the time marginally) more secure.

Windows 10 is technically still Windows NT.

Considering Windows NT 4.0 came out in 1996, I think you may have your facts a bit wrong there.
And NT 3.51 came out in May 30, 1995, so not even a Win95 clone.

Also, NT 3.1 actually more resembled Windows 3.1 than Windows 95. In fact, I believe the recall that the first version of NT was called 3.1 specifically because of that - it wasn't a coincidence.

As jamyskis said above, Windows NT and 9x are completely different product lines. IBM and Microsoft collaborated circa the late 80s to create a next-gen 32bit operating system which became OS2. It was designed by Dave Cutler of VMS fame. After a few incarnations of OS2, Microsoft no longer wanted to collaborate with IBM on the project any more so it split in two (around OS2 1.3 if memory serves correctly), and IBM continued to develop and market the product as OS2 throughout the 90s, while Microsoft took the codebase and forked it into Windows NT.

Windows 95 on the other hand, was a graphical shell on top of MSDOS just like Windows 3.1 and earlier versions of Windows were, the main difference being that Win95 had the GUI bundled and integrated with the underlying DOS operating system. Windows 98 and ME were the latter incarnations of the MSDOS based versions of Windows. All of these are essentially the MSDOS operating system under the hood and are completely unrelated to the Windows NT product in every way.

The NT family of operating systems that spawned from OS2 became Microsoft's high-end enterprise product line, being a proper 32bit OS from the ground up with no ancestry in MSDOS. This continued from the early to late 90s under the product label Windows NT, ending with the NT 4 series product, then continued as Windows 2000 (NT5) -> Windows 2003 Server -> Windows 2008, etc. on the enterprise line.

Windows XP became the first Microsoft operating system designed for the consumer market which was based on the NT kernel and can be seen as a fork or branch of the NT lineage between Windows 2000 and 2003. So under the hood, XP and its predecessors Windows Vista, Windows 7, Windows 8.x, and Windows 10 all can trace their history back to Windows NT and before that to OS2.

The only real overlap the NT family tree of Windows products has with the 90s era DOS based hack Windows products have are some amount of API compatibility to a limited degree, and from Windows NT 4 onward Microsoft borrowed the user interface design it used in its consumer operating system line (the DOS based ones) for the NT series, although the GUI lacked features compared to the consumer OS at any given time up until XP was released when it became the "head branch" of Microsoft's UI development essentially.

Other than the visual similarity of Microsoft switching the NT user interface design from the Windows 3.x styled user interface that NT 3.51 and earlier versions of NT used, to the Windows 9x styled user interface that NT4 and later products in the family had, calling NT a clone of Windows 98 is quite inaccurate on pretty much every possible level. :o)

The easiest way for anyone unfamiliar with the lineage of these products to figure it out though was to try to install and run software designed for one of them on the other. More often than not, the end result was a tragic miserable failure due to the immense incompatibilities and differences between the product lines, especially when it came to video games. :oP

I'll look over the OS via a VM. I'm not sure yet what I'll be doing...

I have a new harddrive yet to install and I wonder if I should put GNU/Linux on it. It's easy enough to put an OS, just which one.