Unlike politicians, operating systems (OS) don’t get a honeymoon with the general public. Windows 7 has been on the market for almost 100 days now, so – as in politics – it’s a good time to review how the software has performed so far. The results are largely positive.

First and foremost, Microsoft has to be pleased with sales, which have been brisk. Just a week after the Windows 7 launch Oct 22, 2009, the sales figures had already bested the company’s expectations. “Compared with the start of Windows Vista, five times as many consumers have opted for the new operating system in the first five days,” Microsoft reported.

Even better: despite millions of new installations, no major problems have been reported. “There have been astonishingly few problems with Windows 7,” says Axel Vahldiek from German computer magazine c’t. He’d know: his magazine fields questions from readers. Unlike the OS’s predecessor, Windows Vista, the questions received by c’t general involve minor issues.

That said, even the little things can rub nerves the wrong way. “The biggest problems are coming from older hardware,” says Axel Vahldiek. If the manufacturer doesn’t produce Windows 7-ready drivers, then the device will either refuse to work under the new OS or offer limited functionality. The difficulties are most prevalent in peripheral devices like scanners with SCSI ports.

The blame shouldn’t necessarily be laid at Microsoft’s door, though. The device makers sometimes make things difficult by design, Vahldiek explains. They might be speculating that those affected by problems will buy new hardware and throw their old devices out if they don’t offer enough functionality. The hardware inside the PC usually works without a problem.

No major security holes have been identified yet. Microsoft clearly learned its lesson from the painful introduction of earlier operating systems. “From a security standpoint, Microsoft’s Windows 7 has made significant progress over its prior versions XP and Vista,” reports the German Federal Agency for Security in Information Technology (BSI). Attacks on the system itself have become so difficult that viruses are instead focusing on vulnerabilities in third-party applications.

The experts at the BSI nevertheless still see some room for improvement: given the strong protection mechanisms in Windows 7, it’s a shame that Microsoft fails to preset all user accounts as “restricted”.

The typical procedure instead requires that an administrator account be set up. This allows potentially vulnerable applications an unnecessarily high level of permissions. “The administrator account that Microsoft has conveniently added for managing user accounts nevertheless fails to represent an effective barrier here.”

The BSI’s grades for Windows 7 are better for the protection of user data using the BitLocker hard drive encryption function. This has been reworked to be significantly more user friendly. Then again, it is also only available in the two most expensive versions of Windows 7: Ultimate and Enterprise.

Because bugs are an inherent part of any software release, especially for software as complicated as modern operating systems, users can expect updates and improvements to start arriving shortly after publication.

In the past, Microsoft has typically rolled up the improvements into multiple Service Packs (SP). No information is available yet on when “SP1″ for Windows 7 can be expected, says Microsoft spokeswoman Irene Nadler.

That’s okay for now, though. Unlike with XP and Vista, users of the new system can also get by just fine with the existing product until SP1 arrives.