Category: Computer/Network
Analysis:
Starting from Windows 2000, Microsoft introduced the "Windows File Protection" function (Windows File Protection). WFP automatically runs in the background, which can prevent important system files from being replaced, greatly improving the stability of the system. But do you know how to use this feature better? How can I limit its buffer size and allow multiple systems to share protected files, thus saving hard drive space? How to make it scan system files directly every time the system is started? After mastering these, we can...
1. Principle of file protection mechanism
When installing new software on the computer, system files and device driver files are sometimes unsigned or incompatible versions, causing system instability. The system files and device driver files shipped with Windows XP are digitally signed by Microsoft, which indicates that these files are original and unaltered system files, or that they have been approved by Microsoft for use with Windows.
How does WFP work? It turns out that when important system files (including sys, dll, ocx, ttf, fon, exe and other types) are replaced or moved, WFP will verify the digital signature of the new file to determine whether the version of the new file is correct Microsoft version, if the file version is incorrect, Windows File Protection will automatically call the DLLCache folder or the backup file stored in Windows to replace the file. If Windows File Protection cannot locate the corresponding file, the system will prompt the user to enter the location or insert the installation CD.
2. System File Checker
Windows’ file protection mechanism is automatic. In fact, we can completely rely on
System File Checker ( System File Checker, abbreviated as SFC) controls the file protection mechanism on its own. Here, we first introduce SFC, and specific examples will be explained below.
The application corresponding to SFC is called sfc.exe, and you can find it under \Windows\system32\. Using it, once a protected system file is found to be replaced or moved, SFC will automatically restore the corresponding file from the \Windows\System32\DLLCache\ folder (Windows XP with SP2 installed has 2169 in its DLLCache folder important files, occupying 364.5MB).
SFC has many parameters. Using these parameters, you can better control file protection.