At uninstallation of Anti-Virus for Microsoft SharePoint, call to STSADM.EXE may fail The uninstallation of Anti-Virus for Microsoft SharePoint tries to revert the SharePoint antivirus settings. This operation may not succeed if you use an account that does not have permissions to change SharePoint settings (changing these settings requires a special account).
Once the uninstallation is complete, log into SharePoint Management Console and make sure the following antivirus settings are switched off: Scan on upload and Scan on download.