Have been a user of the free Avast on Windows XP SP3. Never had a problem with it loading, but today, May 17, 2018, got UI Failed to load. Went to Accessories, System Tools, System Restore and saw a restore point for May 17 with the description Installed Windows XP Wdf01009. Tried restoring to before this change but after rebooting Windows said that it could not restore. Got the same results trying restore points for May 16 and for May 15. I have Windows Update set on manual instead of automatic so I think that this update came from Avast instead of from Microsoft. Tried the solution for UI Failed to load that is recommended by Avast Support to start services.msc in Run and for Terminal Services and for Background Intelligent Transfer Service change from Manual to Automatic, but that did not fix the UI Failed to load problem. Also went to Control Panel, Add/Remove Programs and first used the Avast option to Repair the product and then uninstalled Avast and installed the latest version, which is 18.4.2338, but still get UI Failed to load. Can select About Avast and it says the Release date is 12/31/1969 4:00:00 pm, which is weird. The Windows update does not seem to affect other software, only Avast. It is not cool to install an update that prevents returning to any previous restore point - Microsoft must know more how to do it than does Avast.