Officially, MS say that Office Starter 2010 is 'incompatible' with Windows 10 and will be removed on upgrading to W10. The full Office 2010 is certified to run on W10.
https://answers.microsoft.com/en-us/...2-2c36cdb1936c
Indeed, attempting to upgrade W7 to any version of W10 from 1511 onwards will insist on uninstalling Starter 2010. However, the original release of Windows 10 (build 10240, version 1507) did not uninstall it (an oversight, perhaps?). And having survived the upgrade to W10, all subsequent upgrades leave it installed. I too have a fully functional Starter 2010 running under 1909, originally installed in the OEM W7 from Toshiba.