Hi petermartens,
What NB200 model you have exactly? The HDD recovery option is described here:
http://aps2.toshiba-tro.de/kb0/HTD1303440001R01.htm
Have you created a recovery medium as mentioned in user manual? If yes you can try booting from recovery USB stick with recovery files. The recovery installation will wipe the HDD and restore the original factory settings.
If it doesn’t work it looks like a hardware malfunction. MisterX could be right, this can be a HDD issue…