REDMOND, WA — Despite 10 years in development and the backing of a multibillion software giant, Windows Vista is no less an albatross now than it was when it debuted in January 2007.Microsoft and the developer community, though, have figured out what went wrong with Vista, and the company has vowed not to repeat the mistakes in Windows 7, the next incarnation of the ubiquitous operating system.

How do we not love Vista? MaximumPC.com recently counted the ways and found seven key elements that led to Vista’s reputation as one of the worst Windows OSes ever: instability, incompatibility, performance, user account control, activation, version overload and a notion the e-zine called “one more thing.”

Instability may have been the most shocking. After several years with well-behaved Windows XP, people were more than disconcerted to discover that even with pedestrian hardware configurations and laid-back applications, Vista was even more prone to lockups, crashes and blue screens of death than any of XP’s predecessors had been.

Incompatibility was simply vexing. If Vista didn’t like the way a tried-and-true app – like Adobe Acrobat Reader, iTunes, Trillian and other non-Microsoft must-haves – wanted to play, it simply took its marbles and went home. And it wasn’t just applications that rubbed Vista the wrong way: Herds of printers, scanners, network cards and other hardware ended up in junk heaps because there simply were no drivers for them.

Performance issues live to dog users to this day. Although most new OSes are slow until the initial bugs shake out, Vista continues to drag at system resources and never has managed to live up to the speed promises made before its release.

One of the few areas in which Vista improved upon its predecessors was in the realm of security, but even though the OS lived up to Microsoft’s promises in that regard, improvement came at a steep price: Setting permissions, passwords, user accounts and other bits and pieces is so annoying many users declined to take advantage of the features. In addition, there is very little more aggravating than having to pause mid-action to confirm you really intended to install a new program, communicate with a website or send an instant message.

Another aggravation – though not quite as large as the security measures – is Vista’s software activation procedure. What’s most annoying about user activation is that evidently Microsoft believes there is some reason people are going to pirate the OS most users can’t wait to get off their systems. Not only have users refused to upgrade to XP’s successor in any numbers, but many the ones who were forced into the upgrade rolled back the OS to XP as soon as they were able. Under those circumstances, Vista’s incessant validation against Microsoft’s database just seems bizarre.

Even users who decided they liked Vista – or at least could live with it – were confused by Vista’s inordinate number of versions. In a marked departure from previous Windows OSes – which had been available in at most two versions, pro and home – Vista came in a dizzying array of varieties, ostensibly based on the features buyers thought they’d use or need. The biggest rip: Gotta-have features for gamers and power users were only available in the Ultimate Edition, which cost about $400 and didn’t come with enough working extras to make the price tag worthwhile.

And that dovetails nicely with what MaximumPC called the “one more thing” effect: Taking a page from Steve Jobs’ habit of teasing users with super-sexy, top secret features that had diehard Apple fans salivating and even on-the-fence users leaving their perches, Microsoft promised Windows devotees a horde of new features they wouldn’t be able to live without. Most of them turned out to be sad updates of apps previous Windows incarnations included. The remainder turned out to be significantly less than exciting.