Before you update, it makes sense to run the routine that checks if your PC is up to it. Attach any devices you want to include in the check, then run the routine.

I attached my external HDD and my BluRay drive and ran the check. It initially told me that my Nvidia card wasn't compatible but, when I ran it again a few weeks later, it checked out OK - presumably a new driver had been installed in Windows Updates - and I had no problems with the installation, or since.

If you're on 7, here's a link to the check routine download.