Should I install SP1?

SP1 is out and the emails have started hitting my inbox.  I'm noticing one question being asked more than any other - "Should I install SP1?"

Should I install SP1?

I've handled SP1 a lot since it went RTM back early February.  I've carried out numerous benchmark tests and while SP1 isn't going to be a turbo charger for your PC, the bottom line is that you should notice your PC be more responsive and better when under load than it was before SP1 was installed.  For users who are running a Vista installation and have not yet applied the reliability, compatibility and performance updates that Microsoft has released, then they're going to see a much bigger boost in performance from the application on SP1.

Is installing SP1 dangerous?

I've lost count of the number of SP1 (beta and RTM) installs that I've done or overseen and so far I've not seen a single install go wrong.  That's pretty good going for a service pack - Vista SP1 is the most reliable Windows service pack that I can remember handling.

But ... that shouldn't make you overconfident.  The best policy is to hope for the best and plan for the worst.  At the very minimum make sure that you have all data backed up safely.  If you can add a complete set of drivers to this backup, so much the better.  However, I much prefer to have a full image of the system at hand because this makes restoration a snap. One thing that you want to especially protect against is power outages mid-install - these can be deadly to your Windows install and leave your system in a state where it might not boot into Windows and where you can’t restart the SP1 update.  Make sure that notebooks are connected to the mains outlet and that desktop PCs are connected to a UPS where possible.

A small number of hardware drivers can cause problems with SP1.  If you rely on Windows Update to bring in SP1, you won't get it until your system is ready, otherwise you might have small problems where you might have to reinstall drivers and so on.  Ed Bott has more details about these.  Another point worth bearing in mind is that if you have Windows Vista Ultimate language packs installed, Microsoft needs to update these to be compatible with SP1.  Again, if you rely on Windows Update, you won't go wrong.

Any other advice?

Sure.

• Get rid of SP1 beta/RC If you have a beta or release candidate version of SP1 installed, uninstall it before installing the final version. 
• Check for incompatible applications Got anything that’s on this list installed on your system?  If you do then it is best that you update these applications before installing SP1.
• Don’t expect SP1 to heal a sick system SP1 is a collection of patches and system updates.  It’s not a paramedic, priest or voodoo witch doctor and it’s not going to heal a sick system.  If your system isn’t working right, get to the bottom of that problem before applying SP1.  Putting a service pack over a system that’s got problems will, at best, do nothing, but it’s also got the scope for giving you numerous headaches and a weekend project that you didn’t plan on.
• Plan on each update taking about 90 minutes I always plan on each RTM to SP1 update taking about a 90 minutes.  Usually they are over in about an hour but it’s better to give yourself some extra time in case things don’t go according to plan.

Further reading:  Getting ready for SP1.

Thoughts?  Feelings?  Questions?  Feedback?