This is my approach to applying major service packs:
- empty/clean all temp file locations
- delete all system restore points except last restore point (from Disk Cleanup)
- run chkdsk /r (full disk check with surface scan, automatically fix errors)
- defragment system/boot drive
- disable hibernate and screen saver, set 'never' for other PM events
- check for newer drivers for all devices and update if available
- check for updates to all third-party applications and update if available
- remove, disable, or unplug non-essential devices and peripherals such as audio, LAN, firewire, modems, printers, non-system hard drives, secondary video cards, et. al.
- close or disable all third-party apps and services that run in the background (especially security apps)
Install Service Pack. If successful, then undo/reverse/redo things above where applicable.
- empty/clean all temp file locations
- delete all system restore points except last restore point (from Disk Cleanup)
- run chkdsk /r (full disk check with surface scan, automatically fix errors)
- defragment system/boot drive
- disable hibernate and screen saver, set 'never' for other PM events
- check for newer drivers for all devices and update if available
- check for updates to all third-party applications and update if available
- remove, disable, or unplug non-essential devices and peripherals such as audio, LAN, firewire, modems, printers, non-system hard drives, secondary video cards, et. al.
- close or disable all third-party apps and services that run in the background (especially security apps)
Install Service Pack. If successful, then undo/reverse/redo things above where applicable.