Microsoft on a daily basis releases important Windows Updates and MS Office Updates, if you have the Download Updates automatically option enabled then you can get this updates installed automatically in the background of your PC. but a majority of PC users actually disable this feature of Download Updates Automatically, and there are some users who actually dont have an Internet connection. & hence they cant receive these automatic updates from Microsoft and hence their PC remain prone to new virus/malware attacks & can result in System Crashes also.
By Using WSUS Offline Update Software – you can download all the necessary updates required by Microsoft Windows & MS Office, burn these updates on a DVD or copy them to a USB drive & install it on the PC which is offline & does not have any internet connection.
You can also download Service Packs and also create an ISO images of the downloaded updates which you can burn on a CD/DVD.