The Redmond giant has officially announced that it will fix the problem in all versions of Windows 7 and will also provide the appropriate update to users who have lost their OS support on January 14. We did not know when the patch will be available as part of Windows Update, but we should expect it on February 11, the second Tuesday of the following month, on the occasion of Patch Tuesday.
Microsoft's behavior is not obvious. In the past, the company has consistently ignored the occurrence of really many bugs appearing on systems whose support has ended – and no wonder. An exception was made by the software manufacturer, among others in 2017, when he released a critical patch for WannaCry ransomware raging also on Windows XP, which it lost support in April 2014.
If you have a problem setting the wallpaper in Windows 7, you can uninstall patches KB4534310 and KB4544314, which we do not recommend. Alternatively, it is enough to set the graphic as a background image in a resolution corresponding to the resolution of the displayed image.