Delete Files older than X days
Example Delete all files with starting with blah in Folder “FolderName” older than 30 days.
forfiles -p C:\FolderName -m blah*.* /d -30 -c "cmd /c del @path"
Newer Windows use slightly different parameters - e.g. Windows 2012
forfiles /P "C:\Users\remoteeir\Desktop\PingTest" /M PingTestResults_*.* /D -3 /C "cmd /c del @path"