Power-on self test

process performed by firmware or software routines immediately after a computer or other digital electronic device is powered on

The POST, in most computers, is a self-test[1] that checks the OS(s) available and boots from the OS selected. POST stands for Power On Self Test.[2] Computers that have an operating system perform a POST before loading the OS, and many imbedded systems also do a POST.

A POST usually checks the crucial, files, folders, and components. Once the POST is completed, a selected OS will take control and finish the startup process.[3]

If the POST fails, usually a BSOD displays (Blue Screen of Death, most commonly) and offers recovery options such as safe mode.[4]

Other tools

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LKGC (Last Known Good Configuration) reverts to the last non-problematic, successful bootup.[5] It is similar to System Restore, but its primary function is to allow the user to use the computer normally, unlike System Restore, which does not guarantee a fix. Also, LKGC is unrevertable, unless you successfully bootup again.[6]

System Restore works by allowing the user to open a wizard, then select a "restore point". The user must restart for the point to take effect, but the system will start as normal.[7]

System Repair is typically found on the hard disk of your computer[8] and contains options that can be used to fix the system. However, in serious cases, the OS may need to be reinstalled.[9]

References

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  1. Power On Self Test. Retrieved 5-17-10.
  2. POST Overview. Retrieved 3-4-09.
  3. "Post: Definition, Synonyms and Much More from Answers.com". Answers.com. Archived from the original on 2007-05-10. Retrieved 2010-10-31.
  4. Failing POST. Retrieved July 5, 2007.
  5. What is LKGC? Retrieved 2-4-06.
  6. System Restore/LKGC Comparison. Retrieved November 26, 2007.
  7. "Windows - Official Site for Microsoft Windows 10 Home & Pro OS, laptops, PCs, tablets & more". windows.com.
  8. "System_Repair: Web Search Results from Answers.com". Answers.com. Archived from the original on 2011-04-19. Retrieved 2010-10-31.
  9. http://www.windows.com/Reinstalling_Your_OS[permanent dead link].