You can try deleting the contents of your quarantine folder by going to the folder that the quarantine column shows.
C:\Documents and Settings\All Users\Application Data\Symantec AntiVirus \VirusScan\Quarantine and deleting the contents.
Well something along those lines.
Do not delete the folder, but the contents in the folder.
I guess the quickest way would be to "Select All" then click Shift/Delete, which would then bypass the Recycle Bin.
If that doesn't work it's because you don't have administrator privileges, especially if that file is pertinent for the computer to run, such as a boot up file. So even if you have administertator priviliges, do some research on the file name before you delete it from the quarantine.