n things you may not know about DOS-boxes

• Redirect stderr to stdout with "2>&1", as in "app 2>&1 | head".
• Use PUSHD as a smarter CD command, and POPD to return to your old directory.
• REGEDIT's command-line switches are documented at http://www.robvanderwoude.com/regedit.html. You need to use TYPE to get rid of the Unicode(UCS-2)-ness of the output of REGEDIT /E.
• Here's whatis.bat. It echoes 'dir', 'file' or 'nosuch' as appropriate depending what you feed it. This is surprisingly tricky in DOS.

  @if exist %~s1\nul (echo dir) else if exist %~s1 (echo file) else echo nosuch
  

  It doesn't work on network drives though. I've had better luck with this version:

  @echo off
  setlocal
  set FOO=%~1
  if not "%FOO:~-1%"=="\" set FOO=%FOO%\.
  dir /b/ad %FOO% >nul 2>nul
  if errorlevel 1 (if exist %~1 (echo file) else (echo nosuch)) else echo dir
  

• You can output coloured text with COLOR.
• Find which program will run when you enter its name in a DOS-box with WEAR.EXE (an alternative spelling of "where").
• You can turn on tab completion. (If that doesn't auto-install on download, double-clicking on it should do it, or failing that, right-clicking and selecting "Merge".)
• Tab completion is even better than you think. You can enter a wildcard pattern such as *.txt or *fred* to only skip through matching files on repeated presses of tab.
• You can use "TITLE" to set the title of individual DOS-boxes to distinguish them.
• You can get mouse-based cut-and-paste working again in XP by hitting alt-space, selecting Properties, Options, QuickEdit mode. While you're there, set the Screen Buffer height to 2000 in the Layout pane.
• You can drag files into them from explorer to get the full path of the file.
• You can escape < and > by prefixing them with ^, as in "echo ^<hello^>".
• You can do (very limited) string handling by using "SET /P var=prompt" to set environment variables to user input. But with both search-and-replace and slice notation (see below), it starts to become a lot more interesting.
• You can do (very basic) arithmetic by using "SET /A expression" or "SET /A var=expression".
• Environment variables support string search-and-replace ("%BLAH:old=new%") and slice notation ("%BLAH:~1,5%"). Actually, it's not quite slice notation, since the (optional) second parameter is the string length, not the end position. As in Python, you can use negative values for the first parameter to start n characters back from the end of the string. Use "HELP SET" for more info. (This is only true with command extensions enabled, but they are by default, and there's pretty much never any reason to disable them. Do "HELP CMD"/"HELP IF" to find out all I know about command extensions.)
• In case you've forgotten, DOSKEY still exists. If you've set up a (ifl)"Command prompt here" shortcut on your folders (if not, why not?), make sure it runs "CMD /K DOSKEY" to load DOSKEY. This gives you a history with the arrow keys, which is vital, and "DOSKEY d=dir $*"-style macros (or "DOSKEY export=set $*") to make your life easier (alternatively, do e.g. "echo @dir %* > %windir%\system32\d.bat", but that's ugly).
• Batch files can have the .CMD extension as well as .BAT. By default they seem to be interchangeable, but you may be able to give them different associations.
• COPY can be used to concatenate files. Just put plus signs between the source files.

• You can create one-line reminders for yourself by doing something like: 'AT 11:30 /interactive cmd /c "echo It's 11:30, go drink fizzy beverages!&&pause"'.

  You're better off with this though: in C:\WINDOWS\SYSTEM32 put this in "alarm.bat":

  @if $%2$==$$ echo usage: alarm TIME MESSAGE
  @if not $%2$==$$ at %1 /interactive wscript say.vbs %*
  @at
  

  and this in "say.vbs":

  s = ""
  for each arg in WScript.Arguments
      s = s & arg & " "
  next
  MsgBox s
  

  Then you can do "alarm 12:00 Lunch break!" and get a message box instead of a dos box interrupting you.
• You can delete all temp files in this directory and its subdirectories with: for /F %f in ('dir *.tmp /s/b') do @del %f. Don't forget to double the "%"s if you use it in a batch file.
• Windows stores the environment variables in the registry under HKEY_CURRENT_USER\Environment (for user environment variables) and HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Environment (system environment variables). See also kb Q 104011. (Thanks to René Nyffenegger for that info.) This means you can set them with "REG" on Windows XP or later (see "REG /?") or see http://www.RobVanDerWoude.com/ntregistry.html for an NT-compatible alternative using RegEdit to write temporary files. It needs some FIND/FINDSTR replacement though.

There. Your life is now better. Now type HELP and see how the batch file language has been extended since you last looked. FINDSTR is particularly surprising. FOR now has many many options. And stick SETLOCAL at the top of (almost) all your batch files (or preferably SETLOCAL enableextensions enabledelayedexpansion).

Now install (ifl:)MinGW and forget all this again.