this seems a little obvious but for me i didnt know i had to do this before upgrading to windows 8.1 Depending on the build of your windows 8 (build generally refers to which version you got based on release date etc) youll have a certain number of "important updates" in the windows update section. install all the important updates (optional updates are optional obviously) and then visit windows 8.1 in the windows store. If you've done that then it could be corrupt windows files keeping you from updating.