Re: Need to know what "Temporary Files" are



Kewser wrote:
An error message about low memory prompted me to investigate what is taking up so much space. I went to Disk Cleanup and discovered that by deleting "Temporary files" I will gain over 7 GB of space (25% of my hard drive).

Description given:

"Programs sometimes store temporary information in a TEMP folder. Before a program closes, it usually deletes this information. You can safely delete temporary files that have not been modified in over a week."

Main Question: By allowing Disk Cleanup to delete these, will it ONLY delete files that are safe to delete, judged by its own definition?

Follow-up Questions: Does anyone know what this temporary information is that programs seem to create? ...what its purpose is? ...and why the programs aren't deleting the files on their own?

Thanks in advance to anyone who can help.

As a general rule, Microsoft utilities are pretty safe to use. Microsoft worries about naive users shooting themselves in the foot and then calling Tech Support. They spend a lot of time making everything as idiot proof as they can.
I've used MS disk cleanup on a fair number of machines over the years, and with one exception, it works fine. It zaps anything it sees, right away. It will delete everything in folders named tmp or temp, and a lot of (not all of) files with extensions of .tmp where ever they live. It does not check date stamps and let fresh young temp files survive the purge, it whacks 'em all. The only temp files that live thru a disk clean run are the ones currently open (in use) by active programs, those are spared 'cause Windows marks 'em "in use" and defends them against delete by anything.
One Gotcha. If perchance you are running IBM's Rational Clear Case (an expensive programmers source code control tool used by some companies) disk cleanup is trouble. Clearcase stupidly uses the extension .tmp for important permanent files on your hard drive. This "feature" is one of many good reasons for not using Rational Clearcase.
Assuming you are not running Clearcase (a good bet unless you are a professional programmer concerned about a work machine) just run disk cleanup and don't worry about sparing the young temp files. The advice about letting a week go by before zapping a temp file is a good cautious policy, but in my experience you won't get into trouble using Disk Cleanup to blow 'em all away instantly.

David Starr
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