First, close ALL open programs, including any running in the background, like your AV program, etc.
Click on your start button, then go to Find, then Files or Folders (In Windows XP, go to Start, then Search). In this dialog box, make sure where it says "look in", that it is looking at your C: drive (or, if you have multiple hard drives or partitions, be sure "All Local Drives" is selected) and be sure there is a check in the box next to where it says "include subfolders". (This is in "More Advanced Options" in XP. Also, in Windows XP you need to put checks in the boxes that say "Search hidden files and folders" and "Search system folders".) Now, click your mouse pointer in the box that says "named" (in XP, it says "All or part of the file name") and type the following, exactly as it is here.
*.tmp,*.chk,~*.*
That's asterisk period t m p comma asterisk period c h k comma tilde asterisk period asterisk .....with no spaces.
(The "tilde" is the little squiggle above the Tab key on the left end of your keyboard.....DO NOT FORGET THE TILDE as ~*.* will find all files which begin with ~, but *.* without the tilde would find all files on the drive and you DON'T want to do that!!) To be sure you've got it right, just highlight this ---> *.tmp,*.chk,~*.* <--- copy it and paste it in that box.
Once it finds all the files, it will list them and, at the bottom, it will tell you how many it found. (If you are using Windows XP, and it didn't find any files, open My Computer and click on the Tools menu and choose Folder Options, then click on the View tab and scroll thru that list to be sure "Show hidden files and folders" IS checked and "Hide protected operating system files" is NOT checked. Then try the search again.)
Hit ctrl+a to select them all, then hit your delete key. If it won't delete some of them, that's because they are attached to some program running in the background, so you may have to delete them one at a time. If one or two won't delete, they will probably delete when you reboot next, so don't worry about them. NOTE: Windows XP tends to hang onto temp files more than the earlier versions, so you may run into more that you can't delete. If so, just note the name of the file Windows won't delete and find it in the list, then hit ctrl+a to select them all again, then hold down your control key and click on the one Windows won't delete. This will select all but that one. Try deleting them again. If XP finds another it won't delete, repeat this same process. If this won't work for you, try deleting them in Safe Mode (or go to Start> All Programs> Accessories> System Tools> Disk Cleanup and use the Windows utility to delete them, however this won't find any that are not in your Windows Temp folder) . Bottom line is these particular files will probably be deleted by Windows when you reboot, but then will be recreated again because XP needs them while it's running. So, if you delete all but the ones XP is temporarily hanging onto, you will be fine.
Generally, all of these files and folders (**see below for exceptions) are safe to delete and removing them can solve some crazy problems you may be having. However, if you are concerned about this, leave the files you deleted in your recycle bin for a few days until you are sure all is working properly. This way, you can restore the files from the recycle bin if you have a problem ... or, as is *always* the case when I do this, just permanently delete the files from the recycle bin once you are sure all is well.
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**On rare occasion, I get emails from people telling me that they have programs that NEED their tmp and chk files in order for the program to find previously stored information. First off, I have never seen this in my own experiences with deleting temp files from thousands of machines. And, secondly, I would question the intelligence of any program that stores critical information in tmp or chk files, since these file types are universally known for their temporary nature and many people delete them. The only thing I can suggest is read the instructions and documentation for your programs. If they, in fact, require tmp or chk files stored in a specific folder, do not delete anything in that folder. Personally, if I had a program like this on my computer, I would contact the manufacturer and tell them this is unacceptable and if they didn't change this, I would remove that program from my computer. But, remember, my instructions tell you to leave the files in your recycle bin until you are sure everything is ok and I would suggest you do this if you suspect you may have programs that might require tmp or chk files.
EXAMPLE: It was brought to my attention that some wireless network software creates a file called OEM.tmp and deleting this file will break your Internet connection. So, click the header bar at the top of your Search results and sort the files by file name; then hit ctrl+A to select all, then hold the ctrl key and click OEM.tmp to de-select it, then delete the rest. Evidently, from what I see in my research, this file is deleted by all temp file deletion software, including Windows XP's cleanup utility, so I would hope the maker of this software would wise up to this shortcoming; but until they do, you will have to de-select this one before you delete the files.
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Once they are all deleted, you can save this process as an Icon on your desktop so you can repeat it with one click.
Still inside the Find/Search dialog box, go to the File menu and click on "Save Search"......this will put an icon on your desktop that you can click on any time you want to delete temps again!