Log in to the site admin

Delete the group "Cart Users" from the Manage Groups

Delete all shopping cart components from the modulestore

  • fakegateway.dll
  • flatrateshipping.dll
  • gateway.dll
  • gateway.dll.config
  • gcheckout.dll
  • shoppingcart.dll
  • standardvariant.dll
  • weightbasedfulfilmentprovider.dll
  • Any other DLL's installed for the shopping cart (gateways, other shipping providers, etc)