Common File Formats

This is a quick guide for people new to files and file management.
When you first enter file manager or windows explorer, it can be daunting, especially if you're not from a computing background.
Sometimes you might want to delete rubbish to free up space, but you're worried about removing important things.

Well, this isn't totally definitive, and if you lose data as a result of reading this, it's not my responsibility, but with a bit of luck that shouldn't ever happen anyway.

Executables

These are the actual programs which can be run by your computer or system.

The commonest form by far is EXE, eg. NETPAD.EXE
This, when double-clicked, launches the program.
(These are the files you make links to programs from when adding to your start menu.Simply create a shortcut(Right-click, choose Create Shortcut), cut the shortcut file created(appears at the bottom of Explorer) and paste it into your C:\Windows\Start Menu\.... folder.)

Other executables include COM files, which are for MS-DOS programs, and are always very small,
PIF and BAT files, which tell the system to do things or run programs,
and DLLs, which you can't usually run yourself, but programs can run.These are actually executable programs, but often contain mainly functions and routines.Even so, don't ever delete unless you're sure you won't need them.

In general, you can delete an executable if you're deleting the folder/directory in which it is stored.So if you have an installation of Duke Nukem 3D on your computer, and you unwisely choose to delete it, you simply remove the folder C:\Duke3d and the executable goes with it.If you delete the executable on its own then all the data will remain but you won't be able to run the game.

Documents

This term refers to all sorts of things, but for now we'll concentrate on text documents - that is to say the written word.

TXT files are basic textfiles, editable with any word processing program or simple text editor.Delete them only after checking the contents by double-clicking.
DOC,WRI and RTF files normally require Microsoft Word or some similar commercial word processor.The same thing goes for these as for text files - view them before deleting unless you're removing the whole folder.

HTM or HTML (even SHTML or DHTML) files are web-pages - view these with your browser - you won't be paying to look at them, because they are stored at your end of the phone-line.

Delete them if they contain rubbish, or link them with your favourite HTML editor to make your own little intranet on your computer.Your browser can navigate the inside of your computer just as well as anywhere on the internet, and you can store gigabytes of files safely internally, making the appropriate links, without ever having to worry about flushing your web-cache.
Use this technique for your very favourite webpages.

Multimedia

Sound and Graphics files.

Sound

These will be various, but here are the most common:
WAV,VOC,AU,MP2,MPEG,MPG,MP3,PCM,RAW,SND,AIF,AIFF
These should be listened to before routinely deleting, and if the file is too massive, consider converting to MP3, which is the smallest of the above in terms of space taken.

Graphics

Again, very various, but here are the most common:
BMP,PCX,GIF,JPG,JPEG,TIFF,WMF,JIF
View them with an art-type program such as Paint Shop Pro before deleting - if they are taking too much hard disk space, consider converting to JPG format as this is often the smallest.The two types most used on the internet are GIF and JPG.

Video

These are the largest files of all, and can often be safely deleted to save lots of space.

The common formats are MPEG,AVI and MOV.
Best to delete to the Recycle Bin if they are in a program folder, and then try the program for that folder; often the software will still run.If not, restore from the bin.
If they are in data folders you have made, they can almost always be safely deleted.

In general, multimedia files are the easiest to safely remove from your hard drive.They take up a lot of space, and often exist outside of any installations of software, especially if you browse the 'net a lot.Your web cache will be full of them, and deleting old ones or large ones can save lots and lots of space, especially the sound files.

Help Files

These can be removed if you are sure you won't want to refer to them later.
An average computer has a few hundred megabytes of data stored in helpfiles, and if deleted this is a large saving.However, it can be frustrating to be lost in a program without recourse to the online help.
The common formats are:
HLP,ME,1ST,DIZ,CHM,CNT
The file FILE_ID.DIZ will often have resided in a ZIP file(see later), and will contain a description of what the software is.These can be deleted easily with no danger of trouble.
CHM are new helpfiles based on web-pages.These, and their older but sturdier HLP and CNT cousins, should only be deleted in cases of major space problems, because they contain the online help for programs.The CNT files are contents books for Win95.

In general, use help deletion as a last resort, unless the files are pretty hefty and you are confident with the software.

Backup Files

These are files made by you or by programs to back up material which has changed.
The common formats are:
BAK,anything with a tilde(~) in it, anything with an underscore(_) in it, or any file with a duplicate name and a new extension which resembles the common partner, eg.AUTOEXEC.BAT and AUTOEXEC.OLD - delete AUTOEXEC.OLD safely.

Some programs, such as Microsoft Word or Borland Delphi, make routine backups of your data files in order to help you correct critical mistakes.
Once your project is finished, however, these files are utterly redundant.
If your CV is called MYNAMECV.DOC, there will almost certainly be a file called MYNAMECV.BAK in the same folder put there by Word.You can delete this perfectly safely, especially if your CV is long and full of objects or pictures.

Temporary Files

Again, these will have non-alphabetical extensions, or else by formatted TMP.
You can delete these perfectly easily.

Conclusion

It is very easy to delete data files to save space, so long as you know what's vital and what's just excess.
If you don't want a piece of software at all and its files are definately not shared (delete to the bin and test around to make sure) then you can remove the folder with its name on it.
Otherwise you need to know your files; prudent deletion can save lots of space.A lot can be learned with the Right Click button - selecting PROPERTIES on a DLL file can tell you if it's for a piece of software/hardware you no longer have, in which case you can remove it.
In general, use the bin unless you're absolutely sure you won't need something.

Pork to Bacon Software do not accept any responsibility for loss of data due to deletion, but we hope this brief guide will help spot the larger files which can safely be removed rather than buying a new hard drive.