How do i know if viruses that are quarantined during a scan are healed or is there something else I have to do to make sure that they are gone

quarantining moves the file to a location where it would not be found by any references to it and hence rendering it safe. We suggest you review the files in quarantine and permanently delete them.

You can also do another quick ClamWin scan of the directory where the infected file was located to make sure there isn't a "control" that keeps putting another copy of the virus back. You see this sometimes with the autorun worms on removable drives.

Regards,

Where exactly would I find the quarantine file so that I could delete it.

the quarantine folder is specified in clamwin settings-file locations tab