Thanks for this answer. I have been slowly trying to fix over 2000 errors and of course it is quite time consuming.
Can DW do this, fix the basic errors, automaticlaly? f yes, how? I ran the validation, I see the big list to fix, butdo I still need to fix all, one line at a time, by hand?
Well from the looks of it there are a ton of HTML errors and other things that don't validate and will cause display issues with DW. This is because the standards of pages has changed since it looks like the page was made.
My first suggestion would be to validate your code in DW (File->Validate->Markup). And that will get rid of most of the basics
These are the guys that make these standards http://validator.w3.org/ run the validator. There is also a clean up so it will also cleanup the markup but it may make you pages look not how you intend them to be.
If you are starting out validate as you go along as you will see what is going on or turn on code hint in Dreamweaver
I think that Ottz0 is referring to HTML Tidy on the W3C Validator service. It will go through your page and chuck out a tidied up version but it's not always easy to see how things changed. Also, it will still leave you with some coding to do. For instance, a familiar validation problem is not using alt="" text properly. HTML Tidy will put a warning in your alt="**PUT SOMETING IN HERE**"
The other thing to say is that validated code isn't always good code. Still, 2000 validation problems sounds like a lot of work and plenty of coffee!