Whenever I start my PC, my Avira Antivir Personal-Free Antivirus has detected the following files at Windows/System32 as Trojans : 1. postgres.exe 2. posmaster.exe 3. postmaster.VIR I quarantine them all. But when I restart the System the error message saying the windows missing a file - postgres.exe appeared. Are these viruses? If so, how can I fix the problem? Pliz advice!