A program to tell me what filetypes are in this directory

"You can set WinDirStat to look at a specific folder and it will sum up the file-types

And you can even create a report, which you could parse if you need it for something specific"

"If you're using Windows Vista or 7 and you don't want to install a third party software solution, this can also be accomplished using PowerShell:

Get-ChildItem C:\Windows\System32 | Select-Object Extension | Sort-Object -CaseSensitive Extension | Get-Unique -AsString"