try create a partition on that drive use the partition as the backup drive
Stop already...
There's more than 1 way to create backups without USB ports but why not repair them 1st ? ?
Open Control Panel...right clik Every instance of USB roots and hubs and select uninstall...you will get a warning...ignore it.
Upon re-boot they will all be re-installed...
If this doesn't work post back for backup solutions...