After trying many of the things above, which didn't help or only temporarly I found out what really helps!!!
I used the Repair function of Windows XP
1. Switch off computer
2. Put original Windows-XP CD in
3. Switch computer/laptop on
4. Press any key
5. press space key
6. then don't press any key
7. when you will be asket press R for Repair and then follow the explanation on the screen .
(I learned that from a Microsoft-Hotline-man.)
I did not have files and data which got lost. A few programs had to be reinstalled. But that was worth it. Now erverthing works again!!! I am really happy. Thanks to God. (I did pray that I find a way out and promised to post it if it works. Jesus is Lord!!!)
Under
http://www.hinterwaeldlers-home.de/r...tallation.html I found an even more exact explanation how to repair XP - sorry only in German, but you still get some clues what keys to press.
God bless you all!