Compared to brand computer, although assembly machine has some advantages, being short of good after sale service is the shortage.
 Most computer failures are from software. So before ensuring it’s hardware problem, there’s no need to move the machine to repair. Even it’s hardware problem, you don’t need to take the entire computer out. You could just take out the issued part. Therefore, it seems necessary to get a good knowledge of the diagnosis and test methods for hardware failures, in case later when there’s something wrong with computer, you don’t have to take the entire machine to repair. (of course we don’t any problem with it!).
  Failures and solutions:
  If you want to analyze computer failure across-the-board, then I’m afraid you’d have to write a book, and that would not be an easy job. You know that many newspapers and magazines have introduces about software problems. So here I only talk about some typical symptoms of hardware failure, causes and solutions.

1. Computer startup process.
I. First of all, get to know computer boot process
1) The Bootstrap Loader and self-diagnosis applications stored in ROM would be moved to RAM.
2) As Bootstrap Loader runs, the operation system stored in assistant memory device send system files to RAM.
3) System files IO.sys and Msdos.sys are executed. And at this moment, message “Starting Windows XP” would appear.
4) If there’s the file config.sys,