Please state the error number and OS version XP, Vista, Windows 7. Did you recently do a windows update?

I do not recall seeing an error number.  Windows XP was updated last Friday with security updates for Windows and .NET framework.  I have now reset the computer to an earlier time using System Restore, downloaded the Windows updates again and applied an update to WebsiteX5 to version 9.0.6.1775.  All now appears to be OK.

What I have now done and will do so regularly from now on is to export the project onto a memory stick so that I can update the site on another computer running the same version of Website X5.  I tried copying the folder with all the files to another computer with Website X5, but hit problems such as the header picture not loading causing Website X5 to lock up. 

This problem is a known problem and is not Website X5, It was a Windows update for Netframework rolliong back is one option or unistalling the Windows update for Netframework. According to MIcrosoft it is a clash between earlier versions 1,2,3. The latest version is Version 4. Apart from this it affects the registry thus the error. The directories have to be exactly the same otherwise it looks ata non existent directory. ie. Myoldcomputername/pictures or directory and mynewcomputername/pictures or directory. Therefore exporting is the best option and rids you of this problem.