This error occurs when files are deleted or corrupted Windows registry, especially in XP. Critical system or other files as (software, sam, security, default). This prevents Windows from starting. When you try you get a message like this and the PC reboots itself:
Windows could not start because the following file is missing or corrupt:
/ Windows / system32 / config / system
To repair this file by starting the installer ...
Instead of that message sometimes a blue screen with error code
STOP: c0000218. The same problem is solved with the steps that I include now.
The repair method will explain retains all your files and programs. But it's a good idea to get your data from the hard disk BEFORE follow. The choice is yours ...
Error fix
You'll need a CD or USB Windows XP installation. If your computer does not have CD, USB XP creates the program Rufus (click on that link to download). It is very easy to use and all you need is an ISO of Windows XP.
Then:
1-Configure your PC to boot from CD or USB of XP.
When that is ready restart the PC and ...
If you use the CD
Press a key when quickly get the message Press any key to boot from CD. If you do not have time, restart the computer again and try again.
If you use the USB
The USB created with Rufus program that makes you have commented out the message Press any key to boot from USB. Press any key quickly before it disappears. If you do not timely restart and try again.
The installer for Windows XP files and load drivers. Then comes a blue screen that gives you 3 options.
Click on your keyboard the R key to enter the Recovery Console XP. After a bit you'll see a window like the black background image above.
Wait for the line to appear:
What Windows installation you want to log (To cancel, press ENTER)?
Just above that line is a list of Windows installed. Typically there is only one, described as 1: C: \ Windows.
Write the number of the Windows installation you want to repair. In general you should write the number 1 and press Enter.
Note:
If there are more Windows, choose the appropriate number indicating (2, 3, 4, etc.)
[This step may not be necessary] Your Windows password if you have one and press Enter. If you have no password, just press Enter.
When you leave the line C: \ Windows write one by one all these lines.
Note:
If you do not find the backslash (\) on your keyboard using the shortcut Alt + 92 for writing.
md tmp
(press Enter after this line and each of the following)
copy c: \ windows \ system32 \ config \ system c: \ windows \ tmp \ system.bak
IMPORTANT:
You can get out a message that the file has been copied or not found. Continue anyway.
copy c: \ windows \ system32 \ config \ software c: \ windows \ tmp \ software.bak
copy c: \ windows \ system32 \ config \ sam c: \ windows \ tmp \ sam.bak
copy c: \ windows \ system32 \ config \ security c: \ windows \ tmp \ security.bak
copy c: \ windows \ system32 \ config \ default c: \ windows \ tmp \ default.bak
Follow now writing these lines to delete files from corrupted registry. Do not forget to press Enter after each one:
delete c: \ windows \ system32 \ config \ system
delete c: \ windows \ system32 \ config \ software
delete c: \ windows \ system32 \ config \ sam
delete c: \ windows \ system32 \ config \ security
delete c: \ windows \ system32 \ config \ default
Finally write these lines (more Enter after each) to copy the registry files from the Windows folder recovery:
copy c: \ windows \ repair \ system c: \ windows \ system32 \ config \ system
copy c: \ windows \ repair \ software c: \ windows \ system32 \ config \ software
copy c: \ windows \ repair \ sam c: \ windows \ system32 \ config \ sam
copy c: \ windows \ repair \ security c: \ windows \ system32 \ config \ security
copy c: \ windows \ repair \ default c: \ windows \ system32 \ config \ default
Type exit at the black background window and press Enter. The PC restarts.
IMPORTANT:
Do not press any key for now restart Windows to boot from the hard drive and not from the CD / USB.
That's it. Windows must be started normally and again have access to your stuff.
What to do next
Update drivers
Download the drivers for your motherboard or plate. Also updates your devices (printers, webcam or other). Look for them on the web site of the manufacturer of each.
Upgrade Windows XP
Sign in Start -> All Programs -> Windows Update and do what I tell the page that opens to install XP updates necessary.
Your computer is very slow or malfunctions even after doing those two things? The best thing in this case is that you back up your drive using Windows Easy Transfer. Then format your PC and do a clean install of Windows XP.