DEL

Delete one or more files.

syntax
      DEL [options] [/A:file_attributes] files_to_delete

key
   files_to_delete : This may be a filename, a list of files or a Wildcard 

options 
   /P  Give a Yes/No Prompt before deleting. 
   /F  Ignore read-only setting and delete anyway (FORCE) 
   /S  Delete from all Subfolders (DELTREE)
   /Q  Quiet mode, do not give a Yes/No Prompt before deleting.

   /A  Select files to delete based on file_attributes 

file_attributes:
   R  Read-only    -R  NOT Read-only
   S  System       -S  NOT System
   H  Hidden       -H  NOT Hidden
   A  Archive      -A  NOT Archive

Wildcards: These can be combined with part of a filename

   *  Match any characters
   ?  Match any ONE character

Examples:

To delete HelloWorld.TXT
DEL HelloWorld.TXT

To delete "Hello Big World.TXT"
DEL "Hello Big World.TXT"

To delete all files that start with the letter A
DEL A*

To delete all files that end with the letter A
DEL *A.*

To delete all files with a .DOC extension
DEL *.DOC

To delete all read only files
DEL /a:R *

To delete all files including any that are read only
DEL /F *

Files are sometimes created with the reserved names: CON, AUX, COM1, COM2, COM3, COM4, LPT1, LPT2, LPT3, PRN, NUL
To delete these use the syntax: DEL \\.\C:\somedir\LPT1

Folders
If a folder name is given instead of a file, all files in the folder will be deleted, but the folder itself will not be removed.

Temporary Files
You should clear out TEMP files on a regular basis - this is best done at startup when no applications are running. To delete all files in all subfolders of C:\temp\ but leave the folder structure intact:

   DEL /F /S /Q %TEMP%

When clearing out the TEMP directory it is not generally worthwhile removing the subfolders too - they don't use much space and constantly deleting and recreating them can potentially increase fragmentation within the Master File Table.

Deleting a file will not prevent third party utilities from un-deleting it again, however you can turn any file into a zero-byte file to destroy the file allocation chain like this:

TYPE nul > C:\examples\MyFile.txt
DEL C:\examples\MyFile.txt

ERASE is a synonym for DEL

If Command Extensions are enabled (default)
DEL /S [path]filename(s) will display a list of the files deleted

If Command Extensions are disabled:
DEL /S [path]filename(s) will display a list of any files it cannot find

DELTREE

Previous versions of Windows had the DELTREE command that deletes all files and sub folders, DEL /s will delete all files, RD /s will remove all files and folders including the root folder.

:: DELTREE.cmd
:: From tip 617 at Jsiinc.com
@echo off
pushd %1
del /q *.* 
for /f "Tokens=*" %%G in ('dir /B') do rd /s /q "%%G"
popd 

It devoured my paper, it was a really good paper - Ellen Feiss

Related Commands:

DELPROF Delete NT user profiles
Delrp - Delete a file/directory and NTFS reparse points.(Win 2K ResKit)
RD - Delete folders or entire folder trees ()
CleanMgr - Automated cleanup of Temp files, Internet files, downloaded files, recycle bin
INUSE - updated file replacement utility (may not preserve file permissions)

Delete in-use files with rm (Q120716)
Q320081 - Cannot Delete a File or Folder
Delete files older than X days
How to change the Windows NT recycle bin

Equivalent Linux BASH commands:

rm - Remove files
rmdir - Remove folder(s)