Unlicensed products are not authorized to use. The software products are installed as a trial version. If the product's trial period is over, the products will be converted as a trial version.
In general, the software products are programmed with the protocols to see the date of your computer and set the date. Once the software is installed the date is affixed with the registry keys. The uninstall does not fully clean and remove all the changes local and remote made by the package install. In some keys, the package makes a network change to obtain the short-term key from an external server that checks for a previous install.
Most of the modern software when installed creates entries in the windows registry. When you uninstall the trial version, it won’t remove the data entries from the registry. Thus the products turn unlicensed at times. Overriding of the previously installed trial products can cause these unlicensed issues.