One scenario would be: When installing BCAAA version 6.1, you are prompted to first remove all older versions of BCAAA. When checking Add/Remove Programs, BCAAA is not listed and cannot be uninstalled. Also there is no uninstaller bundled with BCAAA
Note: Confirm that Add/Remove Programs from the Windows Control Panel is not showing Uninstall option for BCAAA agent. If it is then remove BCAAA entry from there.
If that is not available, complete the following steps:
Delete the BCAAA Folder in the program files entry. The default path for this is C:\Program files\Blue Coat Systems\BCAAA