Over at the Windows Team Blog they have a post entitled Windows 7 SP1 Follow-up which details some steps you should take before installing Windows 7 SP1. Solid advice.
These steps include:
– They recommend using Windows Update instead of the full download.
– “backup your PC (and important files) to an external hard drive, DVD/CD or network location.”
– “make sure your device drivers are up to date” (I would also ensure all my apps are up to date)
– “check your PC for any known malware and viruses before installing Windows 7 SP1.”
– “When installing Windows 7 SP1 on a laptop PC, make sure it’s plugged in to an electrical outlet (AC).”
– “Your PC will need to reboot after installing Windows 7 SP1 so make sure you save all your work and close your applications before you begin your installation.”
– “Installing Windows 7 SP1 will require a bit more hard drive space so if you don’t have enough, I recommend running Windows 7’s built-in Disk Cleanup tool to assist in freeing up hard drive space.”
– “For those who may want to free up hard drive space, it is possible to remove the service pack installation specific files after installing Windows 7 SP1. After installing Windows 7 SP1, you can remove the service pack installation files by running Disk Cleanup and clicking on the “Clean up system files” button and checking “Service Pack Backup Files” to free up space. We recommend only doing this a few weeks after installing Windows 7 SP1. Please note that once you do this you will be unable to remove Windows 7 SP1 from your PC.”
*note – I’ve no idea what the difference between doing this and running DISM.exe /online /Cleanup-Image /spsuperseded is or if there is any difference at all.