Known junk file type systems and most applications will produce some temporary files during their operation, and all of them have established extension types. Generally speaking, files belonging to these types can be safely deleted. This method is the safest and most effective way to identify junk files, and it is often used in software to clean up junk files. These file types include: *. ~ */~ *.*.* ~/*.-/*.tmp/*。 _ MP standard temporary file; *. Old/*. SYD temporary backup file; Disk error data discovered and saved by bitsCN@com *. CHK passes through a disk scanner; *. GID help file generated by search index data; MSCREATE。 DIR temporary directory information; 0? . NCH temporary newsgroup caches data; Many software products also consider "*". BAK "is a file type that can be deleted, but in my experience, I advise you not to delete such files at will, because some available backup data generated by applications are named after this extension (such as the backup files of ULTRAEDIT programs), and it will bring a lot of inconvenience to delete them rashly. So when deleting the BAK file, at least make sure you know its source, and there is no need to keep it. The folder that can be deleted is called 1. "C: Windows temp" is a standard temporary folder used during the running of the system and various applications. Because all kinds of data and files temporarily stored here can't be cleaned up in time, a large number of useless files accumulated after a period of time will occupy valuable disk resources, so users should delete junk files under this path regularly to ensure the running efficiency of the system. Here's a more convenient way to make the system clean up automatically at startup. Add the following two lines of commands to AUTOEXEC. BAT files in the root directory of drive c: "c: windows command delta tree/y c: windows temp" and "MD c: windows temp" 2. Temporary INTERNET Folders In Internet Properties-General-Temporary Internet Files Settings, users can set the storage location of the folder and the amount of disk space used. Although using these temporary files for caching helps to improve browsing speed, the accumulated temporary data will undoubtedly consume a lot of disk space, so it is suggested that users can clean them regularly and set an appropriate disk space usage value for them. Generally, it is enough to choose between 40m and 100m according to the size of the C drive. Note that the cleaning of temporary INTERNET folders cannot be directly deleted manually. You should use the disk cleaner in system tools or use the command of INTERNET Properties-General-Delete Temporary Files. Files and folders that can be filtered and deleted (* is a wildcard) In addition to the above junk file types that can be safely deleted, some file types can also be safely deleted, but after filtering, all files of this type cannot be deleted. 1.*.LOG LOG is an extension of the standard log entry file, and many programs will use this type to name their own information files about execution or running status. For example, the log entry file of' Golden Mountain Netdart' is' kavpfw.log'. If users have no special needs, they can choose to delete these log files, or choose the option of closing the log files in related programs, or regularly clean up some unusable and huge log files. Note that when deleting such files, two log files. "Record" and "Unload". Because most programs will use them during uninstallation. In addition, you should keep some log files located in the WINDOWS path, such as POP3. Log, SMTP. Logs, etc. 2.*.TXT text file is probably the most widely distributed file type in the computer. Although they occupy a small amount of disk space, they are obviously too large because they are too scattered. According to the different requirements of users, the text files that can be deleted are also different. I think at least' * log *. You can safely delete the "txt" text file. Some programs use this text file to name their own log entry files, instead of using the log extension, so users can treat the above log files completely, but they should be cautious about such files under the WINDOWS path and root directory (such as BOOTLOG). TXT，SETUPLOG。 TXT and so on. ). Other text files, such as "License". Txt',' register. Txt' and' order. Txt that does not interfere with the normal operation of the program can also be deleted. 3.*.REG REG is the registry data file. Most users know that such files cannot be deleted or modified at will, but there are exceptions. Registry cleaning tool software (such as "super rabbit registry optimization") can help users slim down the registry, clear a large number of invalid data entries in the table, and generate backup registry data files at the same time, which improves the security of use. However, after a period of time, the disk space occupied by these REG files for restoring the original data is also increasing. Use "* Undo *". Reg' parameter searches for such files on disk, and users can safely delete earlier backups. In most cases, this will not only affect the safety of tool operation, but also release more space resources. 4.*.INI and empty folder INI files are files that save initialization parameters and setting information of various applications. Deleting them incorrectly will affect the normal operation of the program. However, in one case, some programs cannot delete their corresponding INI files in time after uninstalling. With more and more software installed, there are more and more such invalid INI files, and most of them are stored in WINDOWS path. Users can clean it regularly, but the principle of safe handling should be that you really know which program generated the INI file and the program has been uninstalled. An empty folder refers to a folder that does not store any files except the folder containing hidden files. Usually they are created by related programs and can be safely deleted if they are not used for a long time. Principles for Dealing with Junk Files The most important principle for finding and deleting junk files is security, followed by effective use of disk space. Don't delete files of unknown types easily. All the above files that can be deleted, if they are read-only, hidden or systematic, should be kept as much as possible unless you are sure that they can be deleted safely. Some types of files are complex (such as text files), and the number is large, and most of them are small. In this case, it can be avoided to spend a lot of time to judge the possibility of safe deletion, but the effect is not great.