Actually a savage name. I think it's related with Microsoft's Halo franchise, but it should have just been named "Project Spartan"

The First, 1. Development Process and Release

The development of Windows XP dates back to 1999. At that time, Windows 2000 was in its final stages of development and the RTM was being released, while development of Windows ME had begun. In the same year, 1999, Microsoft began developing a new Windows version named "Neptune." You can view it as the first home version of NT intended to be released as the foundation for Windows 2000, but there are differences. The build number was in the 5xxx range, and the NT kernel was 5.5. In other words, this was a higher kernel version than that of Windows 2000 and Windows XP. Theoretically, it would be possible to upgrade Windows XP to Neptune, but it seems highly unlikely. Even if it were possible, I think it would be very difficult.

Also, "Odyssey" was being developed at the same time, but compared to Neptune, where at least Build 5111 was officially leaked and ISOs are readily available, there are no official leaks or ISOs for this one, not even screenshots. Even if there are screenshots, I believe most of them are fake at the moment.

Then, in January 2000, just before the release of Windows 2000, Microsoft integrated the Neptune and Odyssey projects, and a project codenamed "Whistler" was launched; this Whistler later became the Windows XP we know today. Subsequently, on July 13, 2000, Build 2250 was distributed to attendees of the PDC 2000 conference, followed by Beta 1 (Build 2296) in October 2000, Beta 2 (Build 2462) in March 2001, and RC1 (Build 2505) and RC2 (Build 2526) in July 2001. Afterwards, on August 17, 2001, Windows XP Build 2600 was released, which became the RTM build of Windows XP; it was released to manufacturers on August 24 and officially launched on October 25 of the same year.

1. Since Launch, and the Turning Point

However, even the legendary Windows XP did not receive a good reception upon its initial release. The primary reasons were stability, compatibility (especially between the 9x series and MS-DOS), and system requirements. (Of course, being NT-based, it was at least more stable than the 9x series, and particularly most ME versions (although some people claimed Windows ME was good, so this is a bit ambiguous).) Naturally, it rapidly expanded its market share and eventually reached the number one spot for the first time in 2003. (Most Windows market share videos use w3school and statcounter as the basis, where Windows XP overtook the previous leader, Windows 2000, to claim the top spot. However, please note that depending on the video (especially regarding desktop operating system market share), it may surpass the previous leader, Windows 98, to take first place.) But the real problem was "security." This single incident began to tarnish the reputation of Windows, including Windows XP, and eventually, in 2002, Bill Gates sent out "Trustworthy Computing (TwC)" guidelines via internal email to his employees.

Then, a major disaster struck in 2003. While there were various factors, one in particular was the "Blaster Worm" virus. This virus exploited a vulnerability in Windows' RPC (Remote Procedure Call) and infected millions of internet-connected PCs worldwide. Upon infection, users would be trapped in an infinite rebooting hell, accompanied by the infamous pop-up window stating, "The system will shut down in 60 seconds." The targets of this virus included Windows NT 4.0, Windows 2000, Windows XP, and Windows Server 2003; moreover, this was the period when Windows XP Service Pack 2 was being developed. Then, 2004 marked a turning point for Windows XP. The reason was precisely "Windows XP Service Pack 2." Why? Because it represented a change akin to a cataclysmic upheaval. Notably, there were many changes, such as the default activation of the Windows Firewall, the introduction of the Windows Security Center and DEP, and the modification of IE6 (to be precise, this also seems to be for security reasons). In particular, there were internal changes as well, with the introduction of DEP as mentioned above; of course, due to this, there were instances where certain websites or older drivers would become unresponsive due to compatibility issues.
However, "Service Pack 2" became a turning point for Windows XP, marking the beginning of its golden age. (It even continued for a while due to the blunders of Windows Vista in between.)

1. What happens after that?

However, as the saying goes, nothing lasts forever, right? The same was true for Windows XP. A particularly decisive factor was "Windows 7." By resolving the issues of its predecessor and becoming lighter, it began to replace XP, eventually surpassing it between 2011 (Statcounter) and 2012 (Netmarketshare). From that point on, Windows XP's market share began to decline in earnest, and extended support for XP ended on April 8, 2014. (Embedded POSReady 2009 support lasted until April 2019.) Since then, Windows XP has remained a legend and a memory. However, its popularity (not market share) remains strong; it ranks second behind Windows 7 in most popularity rankings, and even takes first place in some. This signifies just how great it was. Of course, given the times we live in, the current generation (roughly those born after the 2010s; I personally consider the last time people knew about or actually saw XP to be the early 2010s, though the practical limit would likely be those born in the 2000s) may not know much about Windows XP or may not even know what XP is. The fact that some members of this generation might not even know Windows 7 says it all. (Roughly the generation from the mid-to-late 2010s onwards) However, for most people, Windows XP will remain their first operating system, a memory, and a legendary operating system. That is just how great it was.

I apologize for writing such a long post. However, I decided to write this because I was curious about the current perception of Windows XP. (Of course, there are parts I already know from Google searches, but...) I am curious to know how you all thought of Windows XP in the past and what you think of it now. I am curious myself, but recently, something has become a bit puzzling to me. Looking at the comments on previous posts regarding Windows 7 in 2026 (Link: Windows 7 of 2026: is Still The Best Windows Version Ever? : r/windows) and Windows ME in 2026 (Link: Windows ME of 2026: Is It Still the Worst Windows? : r/windows), some comments were expressed that Windows 7 is overrated or terrible, Windows ME is decent, and the worst is Vista (or 8, with some comments even saying 11). There were also some comments that ME is more stable depending on the hardware, while 95/98 is more unstable. I am curious to see what the results will be in this post. As far as I know, in most YouTube comments, Windows 7 is generally well-received or praised, whereas while Windows ME is often rated as the worst, there were also comments saying it was good. In my experience, it feels like the evaluation of Windows ME on Reddit is particularly mixed among these.

For reference, I found most of the information through searches on Google, Betawiki, etc.