The Windows command del can be used to run a wildcard search to delete any files in a directory containing a particular string.
So you if you have a folder like this one, and you want to delete the files beginning 'Best':
. . .right click in the folder, pressing CTRL + SHIFT, and select 'Open Command Window Here'. Enter the command del followed by a wildcard search using an asterisk.
. . . Windows will then delete all files beginning with 'Best'.