After running an SBS 2003 (SP1) server for the last 2 years without any problems I recently installed Nod32 2.7 and after approx 4 hours the server crashed. On investgation I found that the file monitor AMON was causing the problem. Approx 2 hours after enabling AMON I get the following errors:- DHCP - cant move log file from dhcp because its in use by another process.(not exact message) Lots of DHCP Jet database errors in system log Exchange - an attempt to open file mdb for read/write access failed because its in use by another process.(not exact message) one of the system attendants tasks is blocked Licenesing SBCore - licence store for the client access licenses is not valid. DNS-The DNS server timed out attemting an active directory operation. The server becomes almost unusable until I disable AMON - everthing returns back to normal and system attendant reports "one of the system attendants task has recovered after a long delay." I have excluded exchange from being scanned and also dhcp folder but it makes no difference. The server is a standard install with No additional or bespoke software running. Previously it was running Symantec Corp which uninstalled without any problems. Any suggestions welcome.