Windows Patch: difference between GDR and QFE

Windows Patch: difference between GDR and QFE

|: Computer Application | Tag: Windows, patch |

When we install patches for Windows XP, we often see GDR or qfe in the patches. What do they mean? In the past, Microsoft has already assigned a level for the update system file in the patch. GDR indicates "Normal Distribution version", and QFE indicates "Quick repair project update version ", among them, GDR update files are generally subjected to a large number of rigorous tests, so the patch stability is relatively high, while QFE update files generally do less tests, so its stability is generally inferior to GDR.

Because the update files are classified, Windows patches are also divided into two categories: one is known as the "Security Patch", and the other is a patch package that contains the GDR and QFE versions of the update files, that is, two replicas are usually used to publish key updates when a critical vulnerability is detected in Windows. The second type is called a "hotfix", which is generally a non-critical update, only update files of QFE version are included.

So why does the "Security Patch" contain the versions of the two update files? For example, we want to install a non-critical update that only contains the QFE file. If the old system file to be updated for this patch is already in the GDR version, the update program will automatically compare the version number of the new and old files. If the original GDR file version is higher than the QFE file version in the patch package, the QFE file in the patch package will be automatically disabled for updates, instead, it will use the same QFE version number as the original GDR file. So where can I find this QFE file with the same version number as the original GDR file? The actual file is already in the computer's hard disk, because the same version of QFE has been copied to the system for backup when the "Security Patch" containing the GDR file was last installed. This is why the "Security Patch" must contain both GDR and QFE copies.

For example, if we want to install the kb896688 patch, We need to update the System File % SystemRoot % \ system32 \ mshtml. dll. Because the kb89668 patch is a "security patch", it contains both GDR and QFE versions of mshtml. DLL copies, whose file descriptions are "xpsp_sp2_gdr.051004-1415" and "xpsp.051004-1419", respectively ". After the update program is executed, the installer automatically detects the mshtml of the current system. dll version. If you find that the original file is the GDR version, you will use the GDR version in the patch package to update it. If you find that the original file is the QFE version, it will be updated with the QFE version in the patch package. In either case, after the update, the new system file will be the new version 6.00.2900.2769 after the update, but there are only GDR and QFE.

Now, let's look back at the first example we mentioned in kb896688. Suppose that before we update the kb896688 patch, the original system file mshtml. dll is already the GDR version, then when updating the patch, it will be updated with the GDR version of The xpsp_sp2_gdr.051004-1415 version of mshtml. dll. At the same time, the update program copies the QFE file of xpsp.051004-1419 to the hard disk. The specific location is the $ hf_mig $ sub-folder under the Windows folder. Assuming that we need to install another non-critical patch that also requires mshtml. dll modification in the future, this patch will automatically detect which version of the QFE file we provide is higher than the xpsp_sp2_gdr.051004-1415. If your own QFE version is not as high as the xpsp_sp2_gdr.051004-1415 version, it will not be updated with their own QFE file, in Windows \ $ hf_mig $, the Standby xpsp.051004-1419 will be taken out and updated.