Not back to window xp

When you post a request for help it is a good idea to let us know what model of computer you are using.  From the description of your problem, however, I would say that you have either a Dimension desktop or an Inspiron laptop that is running Windows XP.  The symptom you report indicates that the code that begins the loading of Windows has either become corrupted or unreadable.  A failing hard drive often presents this symptom.

To see if you can determine if your hard drive is failing, start or restart the computer and tap F12 during the self test.  You should get a start-up menu that includes Diagnostics.  Select diagnostics and run the test for the hard drive.  If the test does not report an error, see if you have an option for an extended test of the hard drive and run that.  If both tests are good you should be able to restore the system using the same hard drive.  If you get an error in either test, you need to think about replacing the drive.

If the drive tests good you need to see what you can do about saving any data you wish to keep to external media.  Restoring the drive will put you back in operation, but many of the processes are destructive to any existing data you have on it.