Downloaded Program Files

• This is one of many options in the Disk Cleanup Utility that you can check to have deleted. Checking this will remove any ActiveX controls and Java applets that are downloaded when visiting websites. This only affects these types of files, not actual program files running on your system.
  
  

Temporary Internet Files

• This is one of many options in the Disk Cleanup Utility that you can check to have deleted. When you check this, it will remove all temporary Internet files from the system. This includes, but is not limited to, deleting all temporary cached versions of websites saved to your machine. This does not delete cookies or personal settings.
  
  

Recycle Bin

• This is one of many options in the Disk Cleanup Utility that you can check to have deleted. It will delete anything that is left in the recycle bin. Many people make the mistake of thinking that once they put a file in the Recycle Bin, it's gone. The truth is, until you empty the Recycle Bin, or delete files through Disk Cleanup, they will remain there and take up space on your computer.
  
  

Set up Log Files

• This is one of many options in the Disk Cleanup Utility that you can check to have deleted. These are files that are written when XP was installed on the system and provide a log of all the steps and processes done when XP was installed. It is safe to delete them.
  
  

Backup and Offline Files

• These are two of many options in the Disk Cleanup Utility that you can check to have deleted. They were lumped together as they are similar in nature. Checking the Backup Files will remove the backup of your system that you saved when upgrading from XP. It is safe to check and delete this if you are not planning to revert to your previous operating system. Checking the Offline Files box will delete any web pages that are saved to your system that you chose to be able to access when offline.
  
  

Compress Old Files

• This option, which is the only option that does not delete files, compresses files on the operating system that have not been accessed after a certain period of time. The files aren't deleted, but simply compressed into a smaller size since they aren't being used and can be accessed by the operating system if they are needed once again.