Hi, ok, save yourself some money (and maybe time) and simply reinstall win 10.. (or using a Win 10 bootable medium you may be able to go back to your previous version if < 30 days from installing Win 10).

A clean install is safest. Suggest you format your disk.

If you don't already have a disk or USB or iso, the iso is freely downloadable, and will activate automatically.
Windows 10 ISO Download - Windows 10 Forums