Some older programs not updated to work correctly with Windows 8/8.1 will produce some very undesirable results when uninstalling them, such as clearing out your start and app screens.
Echolink is one program that affects Windows 8 in this way when using its bundled uninstaller. You can read about how to extract the exe to run it as a standalone program in this post.
You can see below a sample of an affected system, and that all the tiles have been removed from the start screen and all apps screen:
In this situation, the search from the start screen is available, but will not produce any results. The only way to navigate is to right-click on the start button and make selections from that menu, or to use the charms bar.
Various sites offer various fixes for this issue, and I haven’t found one that works without either refreshing the PC or having to use a restore point. If you use a restore point to recover, the program will likely be reinstalled. If you refresh your PC, you will keep your data but you may lose some settings or customizations.
For either of these two methods, follow the link below:
How to refresh, reset, or restore your PC [microsoft.com]
I wish I could find a consistent fix without having to use the above, but they methods do work.
If you have a solution that works, please feel free to share it in the comments below. Thank you!