Visit this page at Symantec. The site includes this remark:
"The Microsoft Debugger Registrar for Java (Jdbgmgr.exe) is only used by Microsoft Visual J++ 1.1 developers.
If you follow the e-mail message instructions and delete this file, you do not have to recover it unless you use Microsoft Visual J++ 1.1 to develop Java programs on Windows XP, Windows NT 4.0, Windows 98 Second Edition, Windows 98, or Windows 95."