On this blog and elsewhere, we have received reports of file type associations missing after installing KB2589275.
After installing this update, some users have reported they are unable to open files by double-clicking them, that the file type icons have changed, and that they must go to the application to open files.
We are aware of this issue, and we have been recommending the steps below to correct the problem. We're rolling this up to a blog post to improve visibility and to net in folks who may not understand "File type association" and similar language of software complexity.
You may see this dialog box when trying to double-click to open files:
You may also observe some of the icons related to Office files have changed. Some users have reported the file type icons turn orange, some report the file types appear blank or without the normal Microsoft Office icons.
This happens because the Operating System has lost the association between a file type and the application that it is supposed to open it. This does not change the file, this only affects the relationship between the operating system and the applications associated with the documents. in practical terms, it means that the typical double-click action will fail when trying to open files.
How to fix this issue
There are several options available to repair this issue. Each will restore Office products to a fully functional state. These are permanent fixes rather than having to revert to opening files inside the applications.
1. Use "Open with..." From any file missing its extension, right click and select "Open With", and then select "Microsoft Office Client Virtualization Handler." This will restore the file type to the application. In some cases, you will see "Microsoft Application Virtualization DDE Launcher." Select this option to restore the file type associations. You can also use the "Choose Default Program..." option, select the same option from that list to permanently restore the file type association to the correct Microsoft Office application.
2. In some cases, you may also need to repair the Office 2010 Starter Edition installation to restore all file types. In this case, visit add / remove programs, select Microsoft Office Starter 2010, and select "Change" from the menu bar.
You will be asked whether you want to repair your existing installation. DO NOT SELECT "Remove all Office user settings related to this product" if you wish to keep your settings on the local computer. Click yes when you are ready. It will take a few minutes to complete, and afterward you should be able to open files from your computer using a double-click action.