Windows xp minimal power management

Notebook computer users can specify an alternative power scheme that will take effect when the PC is running on battery power. EPA recommends setting computers to enter system standby or hibernate after 15 to 60 minutes of inactivity. To save even more, set monitors to enter sleep mode after 5 to 20 minutes of inactivity.

The lower the setting, the more energy you save. Developers should examine the file extensions that their applications use in light of System Restore. Files that store user data should not have extensions matching those protected by System Restore, because otherwise users could lose data when rolling back to a restore point. Another area where Microsoft has added a recovery capability to improve system reliability is in driver installation. To protect you from the situation where you install a third-party vendor's driver update that introduces problems, the Hardware Installation Wizard HIW keeps backup copies of replaced drivers.

If you update the same driver again, the HIW will create a new backup and delete the previous one, thus keeping only the most recent backup. A driver's property page in the Device Manager has a button that lets you roll back the driver to the previous version, as seen in Figure 6. It has been integrated with the HIW to make recovery even more likely. One of the most common uses for Last Known Good is to return a system to a bootable state after you've installed a driver that prevents the system from booting successfully—the previous copy of the CurrentControlSet won't have the Registry settings that enable the new driver.

Windows XP has the same driver-signing policy support as Windows where you can configure the system to warn you about, prevent, or silently allow the installation of device drivers that haven't been signed by Microsoft and therefore haven't passed Microsoft driver testing.

Windows XP adds to this a new feature called Driver Protection, which consists of a database of drivers that are known to crash systems. A limitation of many backup utilities relates to open files. If an application has a file open for exclusive access, a backup utility can't gain access to the file's contents. Even if the backup utility can access an open file, an inconsistent backup could be created. Consider an application that updates a file at its beginning and again at its end.

A backup utility that saves the file during this operation might record an image of the file that reflects the start of the file before the application's modification and the end after the modification. If the file is later restored, the application may deem the entire file corrupt, since it might be prepared to handle the case where the beginning has been modified and not the end, but not vice versa.

These two problems illustrate why most backup utilities skip open files altogether. A new facility in Windows XP, called volume shadow copy, allows the built-in backup utility to record consistent views of all files, including open ones. Instead of opening files to back up on the original volume, the backup utility opens them on the shadow volume. A shadow volume represents a point-in-time view of a volume, so whenever the volume shadow copy driver sees a write operation directed at an original volume, it reads a copy of the sectors that will be overwritten into a paging file-backed memory section that's associated with the corresponding shadow volume.

It services read operations directed at the shadow volume of modified sectors from this memory section, and services reads to non-modified areas by reading from the original volume. By relying on the shadow copy facility, the Windows XP backup utility overcomes both of the backup problems related to open files.

The shadow copy service acts as the command center of an extensible backup core that enables ISVs to plug in writers and providers. A writer is a software component that enables shadow copy-aware applications to receive freeze and thaw notifications in order to ensure that backup copies of their data files are internally consistent, whereas providers allow ISVs with unique storage schemes to integrate with the shadow copy service.

For instance, an ISV with mirrored storage devices might define a shadow copy as the frozen half of a split-mirrored volume. Figure 7 shows the relationship between the shadow copy service, writers, and providers. Their names are self-explanatory. The shadow copy API sends the IOCTLs to the logical drives for which snapshots are being taken so that all modifications initiated before the snapshot have completed when the shadow copy is taken, making the file data recorded from a shadow copy consistent in time.

The last area of reliability improvements is in the area of the services infrastructure. Prior to Windows , some services shared a process with other services and some ran in their own process. Windows introduced the generic service host process, Svchost. The goal was to reduce system resources by consolidating the various processes hosting built-in operating system services into a single process.

Or, it could permit the system administrator to configure the system to run certain services in their own processes, which would prevent one service from corrupting the private memory of other unrelated services this capability is not documented or supported yet.

The reason this service needs to be in a separate process is that user-written DLLs are loaded into this process. By having RPC running in its own process, these DLLs cannot adversely affect the operation of the other built-in operating system services.

The reason for the two new service accounts is to improve system security by reducing the privileges that services run with. The account has only a few privileges, and is not a member of the local administrators group. So, if a service that is running under this account is compromised, it cannot take down the whole machine. Driver Verifier in Windows is credited with reducing the number of blue screens that customers faced with Windows NT 4.

Windows XP adds a few new verification options that increase the rigorous testing of driver operations. The user interface has also been improved to make it easier for the administrator to choose verification options, including a new option to automatically verify all unsigned drivers.

Windows NT 4. Although there were some improvements to the underlying defragmentation engine in Windows for example, support for defragmenting NTFS directories , the implementation had limitations, primarily on NTFS volumes, that prevented defragmentation utilities from being as effective as they otherwise could be. Another limitation prevented fine-grained movement of uncompressed NTFS file data—moving a single file cluster moved the 4KB chunk of the file containing the cluster as well. Microsoft virtually rewrote file system defrag support for Windows XP to remove the dependency on compressed-file routines and the Cache Manager.

This means that data movement works at granularity of a single cluster for uncompressed files and that defragmentation works on NTFS volumes with cluster sizes larger than 4KB. Also, defragmentation is now supported on encrypted files.

The other big enhancement is support for online defragmentation of the MFT and most directory and file metadata. Finally, there are a number of odd special cases in the Windows defragmentation interface that made writing a defragmenter especially challenging. In Windows XP, while the defragmentation API interface has remained unchanged, the way you can use it has improved enormously, which means better defragmentation that will result in better system performance.

This functionality is required by backup applications that want to preserve original short names. Another new Win32 API, SetFileValidData, enables applications to efficiently create files without incurring a performance penalty for zero-filling them. Any writes to the tail cause the VDL to grow to the end of the write, and any region between the previous VDL and the start of the write are zero-filled.

Some applications, usually clustered file systems and restore applications, use hardware devices to write data directly into files, bypassing the operating system and file system drivers. In addition, some multimedia applications create very large files and don't want to pay the up-front cost of having a file initially zero-filled, which is what NTFS would normally do when a file is sized.

SetFileValidData therefore requires that the caller have the new SeManageVolumePrivilege enabled, which is by default only assigned to administrators. In the future, this privilege will allow nonadministrators to perform other disk management functions. A file system filter driver is a type of device driver that has been supported since the first version of Windows NT. These drivers are widely used in on-access virus scanners, encryption products, and licensing products that need to see file system changes as they occur.

The routines for which filters are bypassed are those that the Memory Manager calls before and after creating a section backed by a file, ones the Cache Manager calls before and after flushing all or part of a file's modified cached data back to disk, and routines the Memory Manager executes before and after writing dirty mapped-file pages back to a file. The reason that the system bypasses filters for these functions is that it doesn't trust filter drivers.

If a filter doesn't pass these calls down to the underlying file system driver it causes file system data corruption and almost certainly a crash however, there are a lot of things that a filter driver can do to cause crashes. This makes it possible for file system filter drivers to examine these operations and even to fail them, and the runtime can ensure that the underlying file system driver is always invoked when appropriate.

Application installation programs do this in order to ensure that the application runs properly, but at the same time the updated DLL may have incompatibilities with other installed applications.

To use a private copy of a DLL instead of the one in the system directory, an application's installation must include a file named Application. An assembly consists of a group of resources, including DLLs, and an XML manifest file that describes the assembly and its contents.

An application references an assembly through the existence of its own XML manifest. The manifest can be a file in the application's installation directory that has the same name as the application with ".

Abhishek says:. Dave Xnet says:. Leave a Reply Cancel reply Your email address will not be published. Search for:. Related Posts Use process affinity to lock application to a single core Monitor system performane and system health Description of soft and hard page faults Description of the hard disk cache Disable the page file to avoid using the slow HDD.

What does ACPI do? It does handle power management and it also puts almost everything in my little computer universe on one IRQ. This is called IRQ sharing and it is a good thing most of the time. From the Device Manager picture below you can see that my magic number is 9. I hope you are duly impressed ;-.

At this moment, I really only care that I do have power management and how I can control the Power Options settings. Like so many things that you want to control on your computer, Microsoft cleverly put the Power Options in the Control Panel. If you are using the category view of Control Panel you will find it in the "Performance and Maintenance" section. When you open the Power Options, you will see a dialog with tabs. The tabs you see on your computer will depend on your hardware.

In any case, you will have the appropriate tabs for those options that your computer supports. This link will open in its own window and you should read it now for a good overview of the subject. Now that you've read the article and know what you are doing, I want to expand upon a few things. Take a look at my Hibernate tab picture below.

Notice that in order to hibernate your computer, you need to enable hibernation sounds silly but you'd be surprised how many folks can't hibernate because they haven't enabled it.

Also note that you will need hard disk space that is equal to the amount of RAM memory that you have installed in your computer.