http://powershell.com/cs/blogs/tips/archive/2010/02/22/filter-is-faster-than-include.aspxA number of cmdlets provide two parameters that seem to work very similar: -filter and -include: Dir $env:windir - filter * . log Dir $env:windir -include * . log If you have a choice, you should always pick -filter. For starters, it is much faster (4xenCommunityServer 2008.5 (Build: 30929.2835)