When viewing the "Processes" in "Task Manager", "Archive Full Text Index Service.exe" process is using a minimum of 25% CPU usage.
Older Ifilters are installed that may cause this issue.
Stop the Full Text Index Service and:
1) Ensure that Windows 2003 Service Pack 2 is applied, this installs newer versions of the native Office Ifilters.
2) Install the "2007 Office System Converter: Microsoft Filter Pack"
3) Remove any instances of Adobe Acrobat Reader and any older PDF Ifilters and install the following PDF Ifilter from "FoxIT"
Restart the Full Text Index Service.
For newer versions of Archive Manager and newer Operating System versions see this KB: https://support.quest.com/archive-manager/kb/146980
Who is FoxIt?
"Microsoft Corporation has finally chosen Foxit PDF IFilter as it's best solution to index and search within PDF documents..."
FoxIT PDF ifilter tool is used here to troubleshoot and determine if the adobe pdf ifilter is a problem.