I had the same problem and I solved it following the steps of this link: https://developer.salesforce.com/docs/atlas.en-us.sfdx_setup.meta/sfdx_setup/sfdx_setup_uninstall.htm
Hope this solve your problem.
P.D: The steps to solve it: Select Start > Control Panel > Programs > Programs and Features.
Select SFDX CLI, and click Uninstall.
Inside your home directory, delete the .config\sfdx directory.