After much time talking with Adobe I am none the wiser. I can't save for web and just get the error message ' could not complete the export command because of a program error'. However, if I make another user account and access PE9 from the new account then I can save for web!
I didn't have this problem wih PE7 running on Windows 7, so why do have the problem with PE9?
If I reinstall windows 7 the problem goes away for a short period.
Can anyone sort this problem out, since Adobe don't seem to be able to?
Create a folder with name 'Optimized Colors' C:\Program Files (x86)\Adobe\Photoshop Elements 9\Presets OR C:\Program Files\Adobe\Photoshop Elements 9\Presets as the case may be on your machine and then try again.