What does the compressed old file represent during disk cleanup? How do I disable the system from compressing old files?

Q: Recently, when I was cleaning up the disk, I found that there were as many as MB of "Old compressed files", all partitions, and I couldn't remember what I did before. After cleaning, all the compressed files in the partition become blue, and I re-built the system yesterday, after installing XP, I found that the compressed files before formatting the hard disk are still blue. I don't know about the compressed files. What is the problem? Can these compressed files not be generated? How? A: The old file checked out by running the Disk Cleanup Wizard is the file that the user has not accessed or executed other operations on the partition for another period of time (50 days by default, after the execution, the system starts to compress the old files. After the cleaning wizard is executed, the system only compresses this part of the file, not deletes it. The added part of the disk space is only the part saved by compression, for example, if the original data is compressed from 550 MB to MB, the size of the old file after the partition is compressed is 50 MB. If you do not want to automatically compress the old files when cleaning the disk, you can perform the following operations: Method 1: Use the/sageset parameter to start the cleanup program. Method 2: By using the Registry Editor, you can also delete the compressed old file option from the disk cleanup Option List. Run the Registry Editor and go to HKLM/software/Microsoft/Windows/CurrentVersion/Explorer/volumecaches/compress old files. Delete the default data under this item and close the registry editor, in this way, the disk cleanup program will no longer analyze the old files that can be compressed. If you want to restore the tool to the default option, recreate a registry entry at the position you mentioned and enter the guid value you deleted earlier: {B50F5260-0C21-11D2-AB56-00A0C9082678 }.