How to delete temporary files to free up hard drive space

Question: I am trying desperately to find more hard drive space. I’ve already replaced my hard drive once and the computer is getting too old (it’s a 486SX) to warrant spending any more money on it. In my search for anything to erase, I’ve noticed some unusual files in my DOS directory (I’m running Windows 95). There are at least a dozen files with the extension of TMP. One in particular is 19 megabytes so that alone would make a huge difference if I could clear it off my hard drive without causing any harm. Can you tell my what this file is for and whether or not I can delete it?

Answer: Windows 95 creates a special directory called TEMP, usually in the c:windows directory. It keeps files with the extension TMP in there. TMP or temporary files are used by a program as a place to put data when it needs a “holding pen”, sometimes during an install or—occasionally—during normal data operations. Think of it as scrap paper for computers. Also, some programs will dump unsaved data into TMP files when a crash occurs.

The location of the TEMP directory is specified in the autoexec.bat file. Usually, it’s a line like this: TEMP=c:windowstemp. When the computer starts up, it reads this file and an environmental variable is set on the system. An environmental variable is a kind of setting packed away in memory that is readily accessible to a program when it needs certain system information. So in this case, when a program asks the operating system where to put TMP files, the computer can tell it by looking at the TEMP environmental variable.

If the TEMP directory is not specified, or if a program just feels like it, it will put a TMP file in the directory it operates in, or anywhere else, for that matter. There seems to be no rhyme, reason, or rule for this. So you’ll end up with a hard drive littered with these useless files. I couldn’t find any literature on this, but I think systems use the DOS directory to dump TMP files into if the TEMP directory is not specified in the autoexec.bat file.

Typically, you can delete TMP files. Be sure to exit out of Windows first, since sometimes the operating system is using a particular TMP file and won’t let you delete it while it’s in use.

Before you go blowing the big 19-megabyte file away, you might want to rename it to something else first and see if the system complains about it over the next few days. It’s unlikely that the data giant you’re concerned about is anything important. It’s probably just a leftover from some past installation that you aborted or that didn’t clean up after itself. Still, better safe than sorry, so test it by renaming it first, and make sure everything still runs fine.

A free way of cleaning up unnecessary data is to try CCleaner (Crap Cleaner). An even safer way to deal with these files is to let a commercial piece of software handle the cleanup for you. Products like 4Diskclean Gold detect unused files or data clutter and dispose of them for you in a safe manner. 4Diskclean Gold is compatible with all versions of Windows.

If you’re looking for space, another type of file you might consider removing is any with a .SPL extension. They can be usually found in C:WINDOWSspoolprinters. These are files created by Windows in preparation for sending data to a printer. Once the document is printed, the SPL files are no longer needed. Again, if there is any doubt, save copies with different names and see if the system complains. (Of course, it would be a bad idea to delete an .SPL file if a print job is in progress!)