Thanks for the update.
As this is the Commserve, its likely that the uninstall of the wfs you did requires a reboot which makes the uninstall incomplete. So when, re-installing, it sees the wfs agent is still incomplete.
Please follow below steps:
1.) suspend all jobs on commserve, stop commvault services, then perform a reboot. Re-run installation as admin and complete uninstallation process. Then, this will alow a new installation of wfs agent.
2.) If after reboot, you are still unable to complete uninstall and re-install. Take a Commserve DR backup. Go to Windows Control Panel—> uninstall commvault —> select agent to uninstall (Note- this brings up an option to select an option to uninstall all agents or specific agents) —> remove wfs if its still listed and re-install it.
3.)Take a registry backup on commserve. Go to Registry key on Commserve, (HKEY_LOCALMACHINE—>Software —>Commvault (look for an installer and rename it to .old) Re-run installation and check if it allows to re-install wfs.
4.) Ensure you take a DR backup, then Use The microsoft utility cleaner to remove the WFS agent locally on your Commserve, then re-insatll wfs.
5.) If you have exhausted all the above options. finally take a DR back and run Repair on the Commvault instance.
Please take a Commserve DR backup before you proceed with any of the above options.
Also let me know if you are unsure of the steps involved in the above procedure.