To resolve this issue, temporarily disable any third-party applications that may place a lock on the vCenter Converter database. In most cases, this is caused by a backup or antivirus solutions.
You may also prevent this from occurring by excluding the vCenter Converter database files from backup or antivirus scans located in:
C:\ProgramData\VMware\VMware vCenter Converter Standalone\db
or
C:\Documents and Settings\All Users\Application Data\VMware\VMware vCenter Converter Standalone\db