Summary:
Temporary files build up on Windows- based computers from program installations, intrusions, browser activity and certain types of viruses & spyware. By deleting them, you will free up  a lot of hard disk space and improve overall performance.
In addition, it makes it harder for others to see or recover history files and immature programs that do not clean up after themselves. You need to delete these files intentionally from your browser (cache) and hard drive (recycle bin).

Purpose:
To provide manual method for deleting temporary files from Windows and Internet Explorer. These are folders and files that Windows needed at one time but are no longer useful. Everything in these folders are safe to delete.
To provide a source for data destruction software that permanently cleans these files out, automatically to help you protect your security & identity while covering your browsing tracks.

Cleansing
Software
Window Washer

Internet Security Software

Privacy & safety software

Advice:
You can use disk cleansing software to delete these files automatically and to erase these files- permanently from your disk drives- fixed and portable storage devices- prior to backing them up. We suggest that you run a program like Webroot Window Washer daily to prevent a build up of temporary files which become very large over time. You may want to remove them permanently using the data destruction feature since they can be recovered easily to reveal your surfing history, old email, instant messaging, etc.
For especially private files and browsing activities, we suggest Acronis' Disk Cleaner. They were the first to develop a Privacy Expert program and enhanced it to provide a very comprehensive Standards- based cleanser and file delete program for business compliance needs.

For Windows Vista- Windows 7

1.- Click on Start, type "%temp%"in the search box and hit the Enter key. It will open the folder that Windows Vista has designated as the Temporary folder. To remove individual folders or files, hold down your Ctrl key while left-clicking on each item you want delete. Release the Ctrl key when you're finished.
2.- To delete these items, hit your Delete key or click the Organize button on the toolbar menu, followed by the Delete option. You will be prompted to confirm that you wish to Delete Multiple Items. Click on Yes to confirm.
If you would prefer to remove everything inside the Temp folder, click on the Organize button and then choose Select All from the menu. Note: If you're prompted that there are hidden files in this folder, just click on OK to bypass the message. A few hidden files hanging out in the Temp folder are not that important enough to worry about. Again, to delete these items, hit your Delete key or click the Organize button on the toolbar menu, followed by the Delete option. You will be prompted again to confirm that you wish to Delete Multiple Items. Click on Yes to confirm.
3. - After all of the files have been deleted you can close the folder window. Return to your Desktop and empty your Recycle Bin. We suggest re-booting your system when the Empty Recycle bin activity is finished.
Please note, these files are not permanently removed from your PC since there are programs available that can still recover them from your magnetic disk drive(s). A professional Cleansing program, like Disk Cleaner mentioned above, can encrypt them to the point they are virtually unrecoverable.
Tips: You may receive a Error Deleting File or Folder message while the files are being deleted. It means that one of the files is in use by a program you are using right now. Click OK, close all open programs, and repeat the steps above. If you still receive the message, try restarting your PC and repeating the process again.

To manually delete Windows XP temporary files
1. Exit all programs.
(You can leave this web page open or print these instructions.)

2.- On the Windows taskbar, click Start > Run
In the Run dialog box, type the following text:

To manually delete Windows XP temporary files
1. Exit all programs.
(You can leave this web page open or print these instructions.)

2.- On the Windows taskbar, click Start > Run
In the Run dialog box, type the following text:

%temp%

Click OK.

3.- Your Temp folder will open in Windows Explorer.
On the Edit menu, click Select All.
Press Delete.
If you are asked to confirm the deletion, click Yes.
Click OK.

4.- You will need to empty your Recycle bin (easily found on your desktop) to erase these files. We suugest repeating this procedure each month, after a period of heavy useage and when your computer starts to become sluggish.

To clear browser Temporary cache files- Internet Exploer 6, 7 & 8.
Most browsers have similar functions- Chrome, FireFox, etc.
1.- Start Internet Explorer.
Click Tools > Internet Options.

2.- In the Temporary Internet Files section, click Delete Cookies box.
and then click OK.

3.- In the Delete files box, click on Delete File & check Delete all offline content, then click OK.

4.- Click on Settings and select "Automatically" for new versions of stored pages." Move the sliding bar to less than or enter "50" MB to indicated the amount of disk space to use for temporary internet files.

5.- Return to your Desktop and empty your Recycle bin. Please, re-boot your system.

Internet Explorer 8
Click on Tools> Delete Browsing History. Check mark Temporary Internet Files and History.
Close down your browser and re-start it.
We are still trying to ascertain how effective this MS program is. On the outside, it looks more comprehensive but file sizes are increasing. We still suggest a professional cleansing program to eliminate, encrypt and destroy this files for confidentiality purposes.

We suggest going through this process after heavy use and to delete personal financial info on a regular basis. Sometimes, this method will eliminate pesky viruses and spyware that re-install themselves again.