In a recent edition of the Windows Secrets newsletter, Susan Bradley offered "Best practices for trouble-free Windows patching" in which she offered some good suggestions for installing bug fixes, suggestions that also apply to other Operating Systems.
Her second suggestion strikes me as the most significant: reboot before installing patches. Bradley writes " ... rebooting PCs right before installing updates ... reduces the likelihood that some unrelated issue is the cause of problems cropping up during the update process."
I couldn't agree more. Starting off with a freshly-booted, clean system is always safer.
The laptop that I'm writing this on offers a perfect example of little things that can go wrong. The machine has been suspended/resumed many times since the last full boot. The screen shot below shows the volume indicator that's displayed when the volume up/down keys are pressed.
Its usually twice as wide. What happened to the right half of the display? Beats me, but I'm sure it will go back to normal at the next reboot.
Update: It did return to normal after rebooting.
Pessimistic Windows users might also consider running the CHKDSK utility, to insure there are no problems with the file system. This should be done periodically anyway, so before updating the Operating System is as good a time as any. Checking the C disk requires a reboot, offering the chance to kill two birds with one stone.
Microsoft has always advised shutting down anti-malware software before installing a Service Pack. If it's a good idea then, it's also a good idea for the monthly Windows updates. In fact, the less software running alongside the Operating System update the better. I think of it as changing a tire on a moving car.
Another Bradley suggestion that I wholeheartedly agree with is avoiding Registry cleaners. If your worst computing problem is some useless entries in the Windows Registry, you are way ahead of the game. Registry modifications strike me as open heart surgery. One reason I'm a big fan of portable Windows applications is that they are totally divorced from the Registry.
Bradley also suggests checking that the system date/time is correct before patching the system. While her focus is on Windows, this just bit me on an iPad Touch.
The device hadn't been used for a long time and the battery had totally drained. This reset the system clock back to 1970 or so, a fact easily missed since only the time is displayed on the home screen. When updates from the app store kept failing, it took a while before I realized that the culprit was a 40 year-old date.
Finally, the Defensive Computing approach is to assume that a software update or installation will screw things up.
With that in mind, Windows users are best off making a restore point before installing or updating any software. Some software, such as Windows Update, does this automatically, but all software does not.
Before large updates, such as a Windows Service Pack or installing a hugely invasive application (iTunes and VMware come to mind) I make an image backup. In fact, I often make a full backup before running Windows Update. But that's me.
Needless to say, ignoring these suggestions does not guarantee you'll have a problem. But, Defensive Computing is about increasing the odds of things working well.