You need the update if you use Internet Explorer. It updates the built in Flash Player. If, and only if, you never use IE, you can hide the update. Having said that, I, and many others according to Google, had problems with the update failing to install. I had to download and install it manually. I just saw in another forum where people using the latest preview build did not have any problem with installing that update.
Which update killed your computer? In my 16 years of using Windows of different versions, I have never had a problem caused by a Windows update.