Ever since February 4, 2008, the day Windows Vista Service Pack 1 and Windows Server 2008 were released to manufacturing, Microsoft made a move indicating that it was not entirely comfortable to release Vista SP1. At that time, Mike Nash, Corporate Vice President, Windows Product Management, argued that it would take the company another month and a half to release Vista SP1 to end users in order to get some device driver issues our of the way first.

Well, one way or the other, Vista SP1 RTM is out and about. First, Microsoft released the service pack to OEMs and to the 15,000 beta testers, then to Volume Licensing customers and MSDN and TechNet Plus subscribers. Last in line, end users will be able to get a hold of the gold bits of Vista SP1 starting with mid-March, and there's a good reason for this. As you might have guessed it, it's driver problems. And you will be happy to know the device driver issues affect everybody, even Microsoft's own employees.

"Since I installed SP1 RTM on my Vista, I discovered that the system after a boot, CPU usage remained constant at 100%. A deeper analysis shown that 99% of that CPU usage was kernel time. After a Sunday afternoon spent to find a solution, I discovered the problem: I have an old PCMCIA card reader that, if present when I boot the laptop, produces the issue and the behavior described above. When Vista started with CPU ad 100%, even if I removed the card reader, system remained with CPU at 100% (== unusable). The only way to unlock the situation, was to reboot the system (without the card!)," stated Nicola Delfino, industry architect in the Communication Sector/Microsoft Services Division.

The conclusion is rather simple, and can be generalized beyond card readers. "If you discover that your Vista uses 99% of CPU time as 'kernel time', try to analyze peripherals you have installed because there could be a driver that is not working as it should," Delfino added.

The fact that Windows Vista might start experiencing hardware compatibility problems after the integration of SP1 was noted in KB948537 re-released on March 3, 2008. Microsoft pointed out that uninstalling Vista SP1 might be a solution to the hardware problems introduced by the service pack.

"Windows Vista Service Pack 1 (SP1) is an important update for Windows Vista. Windows Vista SP1 contains many reliability and usability updates for Windows Vista. After you install Windows Vista SP1, you may notice that a hardware device or an installed program works differently. Therefore, you may want to uninstall Windows Vista SP1 as a troubleshooting step," Microsoft stated.